how to create an app using the functions in other apps
<p>I need ur help..!</p>

<p>I m creating an app in android. The apps use the functions in the other apps which are already present. I want my app to be standalone. I can't use the functions in those app. </p>

<p>To be more clear, If i create an app for making video calls. The app needs to use the functions in the phone apps. can i just create an instance and use the functions or should i redo all the functions which are required?</p>

<p>It will be helpful if i get to know what will happen wen the app is inserted in the code base and compiled.? where ll the R.java file get created? </p>

<p>Could u suggest me some links to get a detail info about it? </p>
