Whatsapp promised to deliver biometric security to Android users after its iOS users have enjoyed the feature for some and after a short period of beta testing, it's now available for everyone. The latest version of Whatsapp allows you to lock your logs, conversations and the app itself with your enrolled fingerprint. You can do that in the Settings > Account > Privacy > Fingerprint lock after you've updated the app to the latest version, of course. There's also an additional setting for lock timer, which is rather convenient because you probably don't want to unlock your...