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React-Native Server Driven ui

I always wonder how apps like Airbnb, Flipkart, and Swiggy update their UI on the fly. Even if I didn’t update the app, Flipkart shows different UIs during festivals, while Swiggy always changes its UI based on the device location.
How I implement this in my react-native-app?
Webview is the solution?
Kindly help me..
Thanks

There are multiple ways you can go about doing this.
One way would be to use WebViews as you've mentioned, this would make it trivial to change the interfaces as it's entierly controled in the servers. But the main issue with this approch will be performance and non native look and feel. These are the two main advantages of using React Native over hybrid frameworks in the first place and therefor, it wouldn't make much sense to use WebViews everywhere. But if there's a small slice of your application that updates regularly(ex - terms of service) you could use a WebView to do the custom views.
A more common way that's low effort would be to have all the code in place for the different looks, but use feature flags to toggle different views. This would work the same way that a dark theme would work. The amount of customization we can do this way is limited because we need to code everything ahead of time.
Another way is to use server driven UIs. With this approch, you will have a pre defined templates in the client that you them populate on run-time with data from the server. For a very simple example, you could have a header image that could be populated with a seasonal greeting image. But instead of simple things like images, this can be much more visible chagnes as well. (ex - List view instead of Grid View)
One more involved way would be to use code push. This would allow things like seasonal UI changes. But this requires a lot more setup and might not provide the best user experience.

Webview is best because this way you can change the UI and the business logic or UI handling logic.
But you have to develop a minimum architecture for that.
Here is my way.
Develop Host layer to use camera, shared preference, file system etc.
Develop a communication layer which will be responsible for communication between your webview and the host layer so that your webview can access all the required device platform(eg. android or ios) features which can not be normally accessed directly from webview.
So now you can render whatever UI(by HTML and CSS) you want, you can put whatever logic you want via javascript also now you can access all the required device features you really need.
So, now you are the king of your app.
Just you have to keep updating the UI or logic in server when you really need.
Some cons are there like
webview in android is different than our normal browser. Some required features are not available.
Its behaviors is different in different API level. So you have to test it very well. For testing, you can use Genymotion.
It does not work well in some old devices/APIs.
Look and feel really matters. But smart design can fix that problem.
If you want your whole app in a single webview then you have to compromise with page transition feature of android or ios. But again smart animation design will fix that.
But this is just a working solution not a smart solution for server driven UI.
I have used some server driven UI frameworks. But they seems to be overhead and lacks some features.
So there should be a framework by which we can render native UI dynamically from server with corresponding business logic change feature and accessibility of all the possible device functionalities.
A few months before I started to develop a Server driven UI framework. I did it little bit. But due to lack of time I really could not complete it.
If someone interested to contribute in this project feel free to contact with me.
I have a solid idea and architecture for this project.
This framework can create a revolution in the world of app development.
email: bedmad82#gmail.com

Android UI vs Opengl ES 2 UI

this question is more for looking advices
I've developed an almost full user interface in pure c++ and opengl es 2, currently I'm developing that the click/touch events be propagate as in HTML, I can't remember why I decided do a UI in opengl, but now I realize that I'm reinventing the wheel.
so currently I have many "elements", buttons, containers, scrolls, pictures, animated pictures, borders, text, drag-drop's, I can set easily where I want each element, set sounds, and I really don't know how fast and effective it is right now, but I've maked all the fast and memory effective that I can, and I planning to use multi-threading in the future. And my goal is to approach a system like html.
And now that I'm looking for how to implement my UI in native Android (java), I realized that I was in the correct way, all the properties and methods all the structure I'm implementing in c++ and opengl is almost the same as in android, even I think my implementation is easier to use the images and sounds because I've automatized all and I can put it in the assets folder, and in the code only put the name of the file and the program returns it, with and effective memory managment.
the current elements are elements that I need for a game interface, so if I need other kind of element I'd have to write it, but right now, I have all elements that I need, I think so.
maybe my code in c++ is faster than java.
but even with all this, I know I have a lot to do to have a full UI, so can you give some advices or experience, advantages, disadvantages, it worth to continue with the UI, or better learn (beacuse I just know a llitle bit of UI Android) UI Android, modify all my game for use the new arquitecture/system, What do you think?

Phonegap or native for a TV Guide app

I'm planning to create a TV Guide app. The app has to interact with a server to get the data and display it in a timetable. The speed and UX are really important. Nothing flashy, I just want the page and state transitions to be very smooth and the assets/icons to look very good. Is it viable to use Phonegap for this app? I'm more proficient in HTML+CSS+javascript than Java/Obj-C but won't mind going native if it's the best way provide awesome UX.

You can totally do it with phonegap. I'd recommend using a javascript framework as well such as backbone.js for transitions and such.

PhoneGap just wrapps a native-app hull around a browser-application. This means: the phonegap-app must simulate a webbrowser and its javascript-engine. It does not convert your application into a real native app. This makes phonegap-apps slower than native apps.
I made bad experiences with an app that is scrolling through a long table of more than 1000 items, each of them holding five text-strings and two icons. Scrolling through the first 10 or 20 items was reasonable, but at item #50 it became really slow, and beyond item #100 scrolling was almost imposible.
So I wrote a native iPhone-App, and it scrolls at the end of the list as fast as at the beginning.
conclusio:
PhoneGap is fine for simple apps that need little resources. But when dealing with long lists or pages that are made of many different items, phonegap is considerable slower than a native app.

Really the decision to use phonegap comes down to abilities, resources and performance needs. Phonegap will be slower than native just by it's very nature that it's another layer on top of native whereas native is optimized to be as fast as possible. Then the second question is your resources. If you only plan on releasing to one platform and have the ability to build native, that could make the most sense. On the other hand if you don't have the resources and want to build to multiple platforms quicker, phonegap will definitely fill that need.
For frameworks, there is sencha, jquery mobile, Dojo Mobile (I find that framework to be the most difficult to use) and Kendo UI (newest of the bunch but not really free either).
And another great template start is to use Mobile Boilerplate to understand the best practices for an hmtl5 starting page.
http://html5boilerplate.com/mobile

if you use phonegap, it will be more easy to create the app for the other platformes(android WP7 ...)
but improving it will take you much more time.
because to have nice transitions and effects with phonegap , you wil need some libs and frameworks like (jquery mobile ,sencha touch ,dojo framwork)

UI feel and look in Titanium, PhoneGap compared to native

I am about to decide which way to push our smartphone development.
I have read numerous articles about these technologies. I have also created test apps, but wanted to be 100% sure that I get this right.
I am not able to create EXACTLY the same look and feel like native app in PhoneGap because it runs in WebView Controler. And the webish look and feel is as far as I will get with this tech. correct?
(In the example app I have created with PG, the look might be similar, but there is a delay when i click on buttons and the animation is not so fluent as in native apps)
Latest Titanium seems to have changed its approach to WebView, to remedy that lack of look and feel of native apps. My question is (I havent tested this myself). Can I create EXACTLY the same look and feel of an native app with Titanium?
EXACTLY is the key word. I mean can a person tell a difference if app was created with Titanium? because I can definitely tell that app was created with PG.
Final goal is the UX, ppl sense this things, and on smartphones anything that is webish and is suppose to be appish is a bad UX i believe.
Thanks

Compared to PG Titanium is more Native like UI experience but it's kinda problematic for Android.Since it's originally intended for IOS.
Titanium for Android is pretty buggy and can mess you up and the thing that you have to come up with workarounds and if you cant find any then you are stuck.
But if you are okay with that and i can easily advise that Titanium is way to go though it's nearly native (not exactly) which close to exactly.I dont think an average user would understand Titanium .

2) yes, since titanium uses the original UI. your javascript code is wrapped to native Objective c code that creates native elements. only constraint is that your are not as flexible as with real native code written by yourself. but you can write native modules and add them to your projekt. so you're able to expand your project with custom UI too.

iOS UI elements porting on Android

ladies and gentlemen!
Very often on my job I meet the following requirement from the client, when developing android applications: "make it look like and iPhone app".
Yes, I know, that the best way is to offer him canonical Android design with all these patterns like dashboard, using menu button etc... But sometimes this is not the case, as instead, I have to make it look and animate just the same. It's frustrating.
Can you guys, please advice me an android library (if there is one) with iOS-like UI elements? Many thanks in advance, I'm looking forward to hearing from you!

To expand on Martyn's comment, which I agree with.
Perhaps there is a great reason why a client would ask for this, but in many cases I bet they might benefit from being challenged on this requirement. If I was presented with this request, I would first ask "Why?". Perhaps they'd answer as follows:
we need a consistent experience across platforms, or
it will be more cost effective to design once and apply to each platform, or
it doesn't matter why, just do it!
Here are some responses for each:
each user will generally have one phone, and won't require the experience on Android to be identical to iPhone - they only care that it works and looks great on their phone. In fact, an Android user would prefer if you used the UI patterns that are more common to the platform, as opposed designing to match iOS. Likewise for an iPhone user.
we have found that having a designer create a set of creative for iOS allows us to pretty much use the creative as-is for Android. Even though Android might have Tabs on top, versus bottom, we are still able to take the backgrounds, button styles, fonts and color schemes from one platform to the next. There will be slight differences, but overall the brand and look should translate well. Here is an example of porting a single creative design across platforms: http://daleburgosdesign.com/
if they answer in this manner, you might want to consider passing on the job. Pixel perfect matching across platforms is tricky aside from the ideas offered in previous answers (OpenGL and the use of a WebView - via Macarse). If the client can't provide good reasoning for this tricky requirement, then it might be best to search for your next client.
Not a straight forward answer to your question, but I hope you find it helpful!

There is no iphone UI library for android that I know of. What you can do is, get the iphone GUI psd and redo it for 3 sizes of android (for the 3 size ranges) and use the elements of these psd's to theme your application.
I get these kind of similar requirements. Sometimes it wont be much about the looks but about the navigation flow of the application and how new views or activities are animated. From my experience, there is no easy way to do it. So I end up making a lot of adjustments and hacks to get the job done. And I over bill the client. :)
Btw you could also consider libraries such as Sencha Touch, it will look the same in all phones that use a webkit browser.

AFAIK there are no 'iOS-alike' widget libraries for Android.
Because of this, you could reasonably charge the client more for both development and support, thereby providing an incentive to stick with the standard Android UI design and principles.

There is no library to port iphone views to Android but if you are starting both applications from the scratch you have two possible approach to share views between both platforms.
First one is using WebViews and coding HTML, JS and CSS. This kind of app is called hybrid.
Second one is using openGL. You can do it directly or using a framework like cocos2d-x.
Depending on what you are willing to you should choose what to use.