How to check programmatically if an application is installed or not in Android?

Question

We have installed applications programmatically.

1. If the application is already installed in the device the application is open automatically.
2. Otherwis

Answer 1

This code checks to make sure the app is installed, but also checks to make sure it's enabled.

private boolean isAppInstalled(String packageName) {
    PackageManager pm = getPackageManager();
    try {
        pm.getPackageInfo(packageName, PackageManager.GET_ACTIVITIES);
        return pm.getApplicationInfo(packageName, 0).enabled;
    }
    catch (PackageManager.NameNotFoundException e) {
        e.printStackTrace();
        return false;
    }
}