How do I programmatically launch a specific application?

Question

I want to launch a specif application.

I know how to do Intents but I want to avoid the selection menu if there are multiple apps that can handle the intent, I want

Answer 1

in oncreate method call => openApp(); method

private void openApp() {
    String packageName = "com.google.android.gm";
    if (isAppInstalled(activity, packageName))
        startActivity(getPackageManager().getLaunchIntentForPackage(packageName));
    else Toast.makeText(activity, "App not installed", Toast.LENGTH_SHORT).show();
}

public static boolean isAppInstalled(Activity activity, String packageName) {
    PackageManager pm = activity.getPackageManager();
    try {
        pm.getPackageInfo(packageName, PackageManager.GET_ACTIVITIES);
        return true;
    } catch (PackageManager.NameNotFoundException e) {
    }
    return false;
}