java – How do I know if a certain program is installed on my phone?

Question:

In the application, I need to enable the user to send messages through the messengers that are installed on his phone, how do I know if the user has Viber, WhatsApp and similar programs installed?

Answer:

private boolean isPackageInstalled(String packagename, Context context) {
    PackageManager pm = context.getPackageManager();
    try {
        pm.getPackageInfo(packagename, PackageManager.GET_ACTIVITIES);
        return true;
    } catch (NameNotFoundException e) {
        return false;
    }
}

In packagename pass the name of the application package. For example, for Viber it is com.viber.voip