I would like to make android button and able to launch other application if already installed and go to android market if not yet installed.
How to do this?
Try to call the Application activity from your code using the, other application package name and activity name or by the Intent filters which is belongs to that other application you need to call...
Intent newIntent;
newIntent = new Intent("other application Package name","class name");
startActivity(newIntent);
Check whether it is launched or not.
//If it is launched, don't do anything
//If it isn't, then navigate the UI to Google Play Intent.
Intent googlePlay = new Intent(Intent.ACTION_VIEW);
googlePlay.setData(Uri.parse("market://details?id="+"other application package name"));
startActivity(googlePlay);