App Locker

Protect apps with a password or pattern

Prevent people from accessing your apps. You can lock any app installed on the
device, and choose between pattern and password locks.

Anti-Features:

NoSourceSince: Upstream source for this app is no longer available. Either the app went commercial, the repo was dropped, or it has moved to a location currently unknown to us. This usual means there won't be further updates unless the source reappears.
Tracking: The application tracks and reports your activity to somewhere – usually either without your consent, or by default (i.e. you’d have to actively disable it). It’s commonly used for when developers obtain crash logs without the user’s consent, or when an app is useless without some kind of authentication.