June 17, 2013, 3:22 PM — Here's how you can download the WhatsApp Lock app free for Android devices.
1. Go to the Google Play page for the free app WhatsApp Lock.
2. Tap the Install button.
WhatsApp Lock helps protect your privacy by letting you set up a PIN to stop unauthorized access to your messages. You can even see intruders that enter the wrong PIN.
Read more: Ghacks