Is there any way to launch for one mobile app to launch another mobile app, e.g. via a button click?
Example: the org.apache.cordova.camera
plugin allows direct access to the camera on a button click. In the same way, how can one app launch another app?
Try this
Intent LaunchIntent = getPackageManager().getLaunchIntentForPackage("package name here");
startActivity( LaunchIntent );
If you don't know the package name of application that you want to launch then try this
PackageManager pm;
pm = getPackageManager();
// get a list of all installed apps then launch by pakagename.
packages = pm.getInstalledApplications(0);
String packagename = packages.get(position).packageName.toString()
Refer this android-package-manager