How can I get information from another app

Question

I am new to Andorid development.

I am trying to write a small application for Android device. One thing that I want is to get information from another installed application.

EDIT:

I want my application to do A and B, and I found a application that already does part A,so what I am trying to do is to extend the functionality of the existing application

is there a generic way to retrieve information from another app?

Answer 1

@dprogramz gave a really good answer but to build on it you may want to take a look at startActivityForResult if you're looking to get a photo or use input from some external activity.

Documentation is here

Answer 2

What information?

If it is shared information that lives in a shared directory then it shouldn't be any problem at all.

If it is protected information you will have to give your app access to these files.

If it is "real-time" information you will have to invoke an API. take a look at the application class

http://developer.android.com/reference/android/app/Application.html

Answer 3

yes, there is a possibility to extend a app X with a feature A. You can add a new feature B to the app and make it more scalable and realiable, only if- Project is Open-Source: You can contribute to the app via github and push changes. If the owner likes it, you can be hire. OR Download the existing the project, make changes and upload it.