Develop Reference

How to provide the functionalities/features of an android app without the user having to explicitly install it

I'm trying to provide certain functionalities for an android phone that could help people in times of emergencies. (These functionalities are dependent on the phone's sensors.) The only/main approach to achieve this seems to be that of developing an app (and I am currently in the process of developing one). But, what concerns me is that the number of people using an application specifically for emergency purposes is quite low. Even if they do install, when "Insufficient Memory" pops up, an emergency app is very likely to be booted out of the phone.
Are there other ways of providing the functionalities/features of an emergency app, without the users having to explicitly install the app? Or should I just stick with the app?
Certain OEMs provide emergency features as part of their settings. Like for example, in a Samsung phone you can toggle to enable the "Send SOS messages", and then, in case of an emergency, press the power button thrice. In what way could I achieve the same?
Any help would be much appreciated...
Thanks in advance!

Without a proper application installed in user device, you cannot provide the functionality you want.
OEM's also have their applications build and packaged with the system image. If you want it, you need to be in contact with them to include your application in new devices.

Is it possible to build a DPC without enroling with EMM Community?

Since the process of applying for EMM integration takes an unjustifiably big amount of time and the whole process is described as "incredibly painful" by those lucky ones that went through it, I want to know whether is it absolutely needed to become an EMM in order to have a working Device Policy Controller app (DPC).
If you faced this problem, please share the experience.
I am developing for COSU devices and want to go into a kiosk mode. I am aware of existence of ways of how to do it, but they all implement a bunch of workarounds - this is not an option - I want a controllable, safe and robust way of doing this. I don't care about not having the ability for remote managing also.

You can use Google's new Android Management API to manage Android devices without building a DPC or registering as an EMM.

You just want to write an app that uses Device Policy Owner? That's fairly simple, assuming you own the devices. Just install your app, adb shell in, and run the dpm command to set your app as owner. If you're buying in bulk from a manufacturer you can get them to do it for you in the custom image you install (although you may need to explain what you want, it isn't a common usecase).
Of course everything has its limits. This will work, unless the user manages to do a factory reset. Which you can prevent via the UI, but can generally be reached from recovery modes or from unlocking the bootloader. So its safe from casual intrusion, but if someone really wants to get at your device and they have physical access and time, they can.

It is definitely possible to write your own DPC without registering with the EMM community.
The most convenient option for provisioning the devices is via NFC. for example using a second device, as it is quite simple to write a provisioning application.
See Implementing Kiosk Mode in Android (part 3 and 4)
for a good example.
I had a few problems with some Android 5 devices, but since 6.0 it works quite well.

How to emulate android phone operations into emulations in desktop

Is there a way to emulate whatever operation we perform on phone to be displayed in desktop/laptop.
When my physical device is connected to my desktop/laptop, i want an emulator like feature displayed, where whatever operations i perform on phone should be displayed in the emulator.
Can we do this?
If we have any such feature, can they both be synched? meaning if i press some operation on emulator, the operation should be performed on phone.
I heard that, these can be supported like cloud based platforms like perfecto, xamarian, seetest etcc...? How they are achieving this?

Have you tried Genymotion Link HereIt is good emulator where you can download any one model of the phone and you can do whatever you like on phonebo.
other one is Mobogenie,these are two sort of emulators with different operations.

Play store app is used to remotely project your android device on a bigger screen ,but main problem is that your phone must be rooted.
If you are using lollipop see thisHere,it has inbuilt feature

Modify firmware of noname android tablet: first steps

I want to develop a HTML5 app to control doors, lights and other things in my garage. The frontend of will get displayed on a 24/7 turned on screen, that really only displays the app (kiosk mode). So there will be really only the app, no browser controls like back and forth button or url bar, and also no notification bar or back and home buttons of the device. Just the app.
For this I considered 2 options:
Doing it with a raspberry PI & connect a touch screen to i
Doint it on a dead cheap noname Android Tablet
Since the 2nd option is much more elegant from the hardware point of view (everything I need is already built in) I decided to try this first and bought a 70 USD Prestigio Tablet.
But since I'm no android dev, I'm not sure how I can even modify the stock firmware that's currently installed on the device.
As far as I can see, the bootloader is unlocked and ready for flashing a modified firmware image.
And here comes the question:
How can I get the device's currently installed firmware image? Do I have to contact the manufacturer for this or can I extract it from the device directly?
If I get the firmware image, how will I be able to modify files in it?
Or do you think I got the wrong route?

You need to find sources of firmware for your specific device. I bet manufacturer would not provide them. For Nexus devices it is easier because there is AOSP (android open source project) which gives you an opportunity to build a firmware. You can also check specific forums like 4pda.
But there is another way - to make a KIOSK mode for your device example. I'm not sure how does that fit into requirements. Also You can make your app as Launcher app and live with that :)

How can I achieve installing apks from server like android market?

I am in the middle of developing an application when I had this idea to allow some applications to be installed in the android device only through a server.
Now I am short of ideas on how to approach this.
An Example of what I want to achieve is the android market website that when you login and synchronize your device, you can see the different applications that you have already installed in your device and also you can install applications onto your device without the application asking for permission to install.
Please if anyone has any idea or a good suggestion as to how I can accomplish this task (both for the server and the android codes) I would so appreciate it.

Unfortunately, on non-rooted phones or ROMs that you don't fully control it is not possible to install an .apk in the background without user interaction.
If however you decide to only target rooted phones or you have your own custom ROM on which this would work, it is just a matter of sending apps to the phone, and then installing them, for which you can find all the code you need in the Android OS source-code.