Develop Reference

Writing for iOS and Android - possible for this function?

Read a number of questions on writing in just one language for both iOS and Android and what I learned is that it depends on the special functions you need. What I want to build is a very simple app that will ask the user what he or she is doing. We need this for billing the customers but my co-workers keep forgetting to update their time-sheet, so I want to write this little app that pops-up every x minutes and asks them what their doing. At the end of the day the list will be sent by e-mail or whatever.
Anyway.... is a pop-up from an app from the background a 'special' function? Can a general language be used on both for this?
Edit: I have searched for crossplatform tools, but all replies talk about specific functions that still require native coding. That is why I was wondering if something as simple as a popup with question and entering / saving a text, would be native or could easily be handled with a crossplatform tool.

You may use Xamarin to create a cross platform applications. I am satisfied with Xamarin platform at the moment. I have been working on native iOS, java for Android also.
Please keep in your mind that, it would be great if you are familar with these platforms because Xamarin is just a wrapper of methods which exist in the native platforms. Since I am familar with native Android and iOS, it makes me comfortable when I work on Xamarin platform.
My personal recommendation is to stick with Native platform. But if you have to work on cross platform, I believe Xamarin is a good option.
Pros:
If you are familiar with C#, it will help you a lot to develop an application for android, ios and windows platforms in Xamarin.
It is demanding platforms, and many big companies are looking Xamarin developers especially after the Microsoft acquisition.
Cons:
You need to buy a license.
There are other platforms as well, but I did not use any of them. Here are some of them
Cordova
HTML5
Unity
PhoneGap
Appcelerator
Corona
Qt
You may find useful the following urls
http://appindex.com/blog/ten-best-cross-platform-development-mobile-enterprises/
http://www.developereconomics.com/pros-cons-top-5-cross-platform-tools/

For sure what you describe can be achieved with using Ionic. Its a free solution and it comes with a lot of good documentation to get you up and running quickly. You'll need to use AngularJS for developing apps with Ionic so that might be a good solution if you know your way around that framework, or if you are familiar with Javascript or have done some web development before.
On regards to your question regarding native functionality (by popups I assume you mean notifications) Ionic sits on top of Cordova so there is a huge amount of native plugins that you can use to implement native functionality. You can take a look at plugins here.
Hope this helps!

Which approach should I take for my mobile application?

We will develop a, social network integrated mobile application which will need to access native device capabilities but 90% of the logic will be implemented in the HTML5/Javascript code posted by Ruby back end to the device. Thus, we would like to update or change the logic/GUI of the app without user involvement. We have strict deadline and have to support iOS, Android and Blackberry.
In this case, what approach would you recommend us? We considered the approaches below but could not decide since we do not have any experience with mobile development even if we are experienced in Ruby, C/C++, Java, Javascript, Flex.
Our considerations:
Develop native apps for each platform and embed the native browsers
to implement our logic, which can take too much time.
Use one of the frameworks for cross-platform development such as
PhoneGap or rhomobile. In this case, we are afraid of facing some performance issues. We would love to hear the experience of developers with those frameworks.
Use Adobe Air for accessing the device and its WebKit component for the rest.

First, I hope you understand that there is no simple answer. At this junction, having been looking at cross-platform solutions for mobile development for two years, I feel that in order to get fully native UI look, and to access all the device and UI features, one is forced to produce native application on each platform.
But, since you asked about cross-platform tools, here's a list of the main contenders:
Sencha http://www.sencha.com/products/touch “Sencha Touch is the world's first app framework built specifically to leverage HTML5, CSS3, and Javascript”
Dojo http://dojotoolkit.org “Dojo saves you time, delivers powerful performance, and scales with your development process”
Phonegap http://www.phonegap.com “PhoneGap is an open source implementation of open standards”
jQuery Mobile http://jquerymobile.com “Touch-Optimized Web Framework for Smartphones & Tablets A unified user interface system across all popular mobile device platforms”
Rhomobile http://rhomobile.com “Free and open source mobile application framework”
Titanium from Appcelerator http://www.appcelerator.com
There are plenty of comparisons online, including on SO, and this fellow actually tried to use several platforms, code included.
Anecdotally, I have seen Phonegap produce a rather iPhone-centric look, that may not mesh well with Android, plus showing performance problems when loading screens (there may be workarounds via pre-loading). Also, access to more complex devices was limited, or at least lagging. Rhomobile is a good fit for data-driven apps (simple display of large databases), but architecturally could show performance issues, so check for yourself. Personally I did not get into Sencha, Dojo seemed a little small, and Titanium showed dated architecture. So next time I'm attempting a cross-platform app, I'll give jQuery Mobile a serious try.
Let us know what you pick and how it works out.

Iam using this rhomobile rhodes for my cross-platform development App which will run in Android, Blackberry and iPhone.
We have developed application and sucessfully runned in all devices without any issues. we used ruby for backend webservice call, And remaining app is constructed with HTML5 and java Script. I didn't face any issues regarding rhomobile.
intially we faced memory issues, But later on we resolved this issue by implementing local storage for our App. For android it wont supports local storage so we used Rhom Storage only for Android Device.

Sounds like a project doomed to fail.
If I were you, I'd build a mobile-friendly site for all 3 platforms if deadline is tight. What native features do you even need, first off? If it's something like a camera, you're better off just build a native app for all 3.

Cross-platform and good performance mobile application for iPhone and Android

I need to develop an Application for both iPhone and Android platforms. I am looking for a cross-platform development frameworks. The important factors need to be taken into consideration are :
The App will be running in intranet environment (with NO internet
connection).
Drag and drop features will be available in this App.
Needs to use the barcode reader library.
Needs to use map (it will probably be a custom map)
Receives Push notifications (currently I have mqtt in mind, since
there is not internet connection)
If possible I only want to maintain only one source code for both platforms. I have done some research and I found 2 frameworks which are PhoneGap and Mono(touch and droid).
PhoneGap seems to be slow.
Mono need two code base for 2 platforms, only the libraries can be
shared (correct me if I am wrong). This is my another worries about mono: http://redth.info/2010/04/09/is-monotouch-now-dead-in-the-water-what-does-apples-new-iphone-developer-agreement-mean
I know the native is the best but for the sake of maintenance and reusing our developer talent (which are C#, HTML, JavaScript) we need to find out the second best option.
Note : Please bear in mind the first 5 features listed on top for your answer.
Thanks in advance.
UPDATE:
After exploring a few more tools, I like the performance of Appcelerator as well. But writing the whole app in JavaScript looks very messy to me and can't use OOP. And the extra package size of (5~7 MB) is also something to take note for frequent releases environment. I like to hear from you guys as well. I will be updating our decision in coming few weeks.

This recent article here may be helpful. It contains a rundown of several new cross platform mobile frameworks including Mono, Appcelerator Titanium, Rhodes, PhoneGap, MoSync and Moai.
From reading your requirements I'd say that either MoSync or Titanium might be the best fit for you. Apart from PhoneGap, which is really just a web app running inside a mobile browser (and might be the reason you thought it was slow), they all generate native UI code apps.

You may want to look into this article comparing 5 different cross-platform mobile development tools.
This Wikipedia article may be helpful as well.

go for http://www.appcelerator.com/
They first compile code in native code so performance is like native and they have barcode reader, push notification (via urban airship) too...

How about doing a hybrid application, using a mixture of native code and HTML5. Write native code for all the IO, and heavy lifting, and for the GUI use jQuery or similar in a web control embedded in your app. Android has a web control that allows you to interact with javascript. I assume you can do the same with Apple. I'm trying to do something similar myself using Monodroid, and its looking very promising, although I discovered Monodroid does not have native Javascript interface yet.

Just so you know, we were using Appcelerator at my last company, and the performance for Android was less than desirable. Our lead developer found the Mono products, and hasn't looked back.

Flex and Action Scripts

I'm instructed to develop a project in such a way that it is available for iOS, Android and Blackberry OS platform all at once. A herculean task!! indeed...
I am searching for all the possible development platforms for this assignment. I came across Flex 4.5.1 and the initial thoughts are really positive. Somewhere in SO I read that flex applications suffer from code bloating problem. I dont want such solution; infact memory is an important concern for me.
I want to know which one of the following is the optimum approach:
Developing using OS specific SDK i.e. xCode for iPhone, Andriod SDK for Android.
Developing using Flex builder and ignore code bloating.
Using Flash Builder and developing application in ActionScript.
I would also love to know if there is any other platform / language / API available for me...
Thanks for your time,

Flash Player's ubiquitous delivery makes developing and packaging mobile applications easy; however, HTML5 / JavaScript platforms such as PhoneGap would also enable rapid cross platform delivery.
Flex is heavier than Pure ActionScript. Depending on what you're developing, Flash Professional or a pure ActionScript project in Flash Builder may meet needs in a very lean and performant manner.

few days back I also asked a similar question here on SO and unfortunately so far I have not got the answer I wanted. (question is still open and you can share your findings with me there..)
Regarding your questions about Flex 4.5.1, I would like to say it is very neat and nearly perfect programming platform and learning it is quite simple. The Support & training available from Adobe is just awesome. You can easily get confidence in just few weeks. See an Excellent Downloadable tutorial, I would suggest you follow it for initial weeks.
In Flex, We Program in .mxml files and ActionScripts(.as) ... *.mxml files are converted to ActionScript during compilation. To increase the efficiency you can directly program in ActionScripts once you understand how they actually work. (Which I am trying to learn now.)
I am not sure about C/ C++ but Flex definitely supports some other languages i.e. Java, PHP etc. For Java developers like me another surprisingly good thing is that Flex can be integrated with Spring also.
Share your findings about Flex..

There are a quite a few cross platform mobile development tools
phoneGap
Appcelerator
Rho mobile
Mosync
Sencha
Corona
WidgetPad
Each one has their own advantages and disadvantages. For example, the applications built using phoneGap uses a html view to show the UI while Appcelerator uses native UI components which offers better UI responsiveness. Some are free and some are not. So you need to decide on your requirements and choose a framework.

If you like HTML5/JavaScript and want to extend it with C++ then you should try MoSync, it gives you the flexibility to blend them all if you so like. You can find out more at mosync.com.

Appcelerator vs Android SDK

I have been looking at appcelerator it seems pretty fine! Without a doubt, one of the advantages of appcelerator is its support for multi-platform. I am interested in building an android app and maybe a iphone app later on. So it is not crucial to support multiple platforms at the moment.
If you disregard supporting multiple platforms and just focus on android development. Is appcelerator still advantageous? Does it lack any features of "Android sdk"?
(When I say "Andorid sdk" I mean development with Eclipse with native Android sdk, if it makes any sense)

We looked at Appcelerator when starting our Android project. We knew we would have to do an iOS client next, so Appcelerator was enticing.
We decided not to go that route because it doesn't support all the native features of each device.
For example, we decided early on that our user interface in Android would need a widget. No support for that in Appcelerator, as it's specific to Android. [This was a few months back -you may want to check again].
Compromising on the user interface was too much for us. We decided to go with C/C++ for the app logic and use Android SDK for the user interface.
Our apps now have two pieces: C/C++ as much as possible to the "brains" and the native (Android/Cocoa Touch) for the UI to take advantage of the UI experience.
Works of course for platforms that can integrate C/C++.
The parting advice: design your user interface first, then find a tool that can implement it. Users have high expectations of the UI in portable devices. Compromising on it early on may be the KOD for your project.
[EDIT] Every so often I see an upvote for this question. I would like to update with what we learned in the past two years:
Using C/C++ for the common parts of our application has paid off. It does require a slightly more complicated build process, but the savings are gigantic if the piece of code being shared is complex (as in our case).
For the user interface piece we are beginning to look into hybrid apps (some UI elements in HTML). There are still debates out there about HTML interfaces (Facebook and LinkedIn are two that move to native code for the UI), but also some reports that when chosen carefully it works. There is a great talk from Flipoard on that; with slides here.
UPDATE Oct/2014
In March/2014 Smashing Magazine published an excellent article comparing native iOS, native Android, PhongeGap (Cordova) and Appcelerator Titanium. They show the development of a simple app in each environment.
This is the last part of the series. At the top of this part there are links to the previous parts of the series and at the bottom there is the comparison of the approaches. There are also interesting comments from readers at the end.
UPDATE May/2015
Still get an upvote for this question every so often, so I would like to share what we have done since I wrote the first part of the answer.
We are now working on a project that also has a web client. We have now the iOS client, the Android client, plus the web client.
JavaScript is the natural choice for the web client.
Since we want to share as much code (at the business logic layer) across these clients, it means we need to find a way to run the JavaScript code in iOS and Android.
And that's what we ended up doing.
This is a summary of how we handle it:
For all clients: all data structures are defined with Google's protobuf. This allows to automatically generate the serialization/deserialization code for iOS and Android.
iOS: run the JavaScript code with the help of JavaScriptCore (a good overview here).
Android: run the JavaScript code with the help of Google's V8 engine.
The bridge between JavaScript and the iOS/Android layer can be a bottleneck, especially the serialization of the objects. We had to optimize a few things and learned a few lessons to stay out of trouble.
Generally the experience has been positive. We saved significant amount of time by sharing the code across all clients.
If I had to start another project like this one (that requires sharing code with web and mobile clients), I would also take a look at what Google did for inbox. It wasn't available when we started. Looks promising.
UPDATE August/2015
And the world keeps turning...
I would also take a good look at React Native if I had to start a new mobile app now.
It's based on JavaScript, bridging web and mobile development more easily.
There is a great tutorial in Ray Wenderlich's site.
UPDATE February 2016
My shortlist for cross-platform development is down to two:
ionic
React Native
I've been paying more attention to ionic because our web app uses AngularJS and so does ionic (Cordova + AngularJS). React Native will force the team to learn another framework (of course the argument is the opposite if your web app uses React).
Nevertheless, I'd seriously consider React Native, even having to learn another framework, because of the reported performance and look-and-feel of the app. From React Native's site:
With React Native, you can use the standard platform components such
as UITabBar on iOS and Drawer on Android
If you are starting now, I recommend you take the time to at a minimum complete their tutorials so you get a better feeling of each framework. Each tutorial can be complete in one to two hours:
ionic tutorial
React Native tutorial
For a simpler approach: Smashing Magazine just published (at the time I wrote this update) a good article showing how to use the native navigation elements to make the app feel (well...) native, while using web views to render the content. The article goes into the details of how to make the HTML/CSS usable in the mobile devices (it's not just pushing the HTML/CSS you already have).

If you only focus on develop apps for Android platform, I recommend you should use native Android (Eclipse + Android SDK as you said) instead Titanium.
Reason: Titanium is suitable if
You want to develop apps quicly, or
Your apps is simple, or
You see Java is so difficult (maybe :p ), so you choose the easier (Javascript of Titanium).
And here is the reasons why you should use native Android instead Titanium:
You want to develop a complex app, or
You want to customize app appearance. It's very important. Imaging you make an app for client, and they need their app to be customized for more eye-catching. Choosing Titanium means you must use their control, which lacks of ability to customize. It'd be better if using native Android that you can customize everything you want.

that is a very difficult question to answer without any specifics regarding the requirements of the application.
I would suggest you take a quick look at the API documentation of Appcelerator to see what the framework provides and also take a moment to list the basic requirements of your application and then determine what tool will be best for your project.

I think you are onto a good start using Appcelerator, since it uses JavaScript, etc. Easy to learn, but good examples. It will also enable you to use the same code and reach iPhone,iPad apps. Learning to use just the Android SDK is more complicated. Even then you still need to develop later iPhone etc apps. If you come from a web background this makes sense. There are good video's for quick learning. Good Luck

My experiences with Appcelerator seem to suggest they are more of an iOS shop. Their toolset for Android is, IMHO, quite lacking. ADT supports visual UI building and debugging on device, which Titanium Studio does not. There has been a bug filed about this for several months now, and it continues to be delayed. If your focus is Android, use Google ADT or MOTODEV Studio for Android. These IDEs are quite nice and are used by professionals.
The above answer presents a great way to develop mobile apps. DO NOT COMPROMISE ON A HIGH-QUALITY USER EXPERIENCE.

Lacking of bluetooth support is a huge deficiency for Appcelerator and no one gives a clue about roadmap.
edit : appcelerator now have BT support in Tizen 3.1

Well, in the new version of appcelerator (APPCELERATORSTUDIO 4.0) you can have alloy projects, and something like css files for your UI (tss), so in fact they are really customizable.
Greatings

Appcelerator has a lot of support and it really easy to use. It supports 100% of native api calls now. They have really good documentation too.