Vault

Even if you normally have your phone locked with a PIN or password, there is still a chance that someone who knows it might have access to personal information. One way to secure that information is to install something like Vault, to make sure that you’re the only with true access.
 
With the help of Vault, users can hide their photos and videos, hide SMS messages, protect the identity of contacts, obfuscate the call logs, and protect your social, photo, call logs and telephone apps to prevent privacy leak.
 
Also, the application comes with its own Incognito browser, cloud backup for increased security, a call reminder that can also act as a filter for spam, and the option to move all your data to a new device.