By locking do you mean hiding?
I personally use Hide It Pro, it appears in your phone as "Audio Manager" and you can access the actual app via a hidden mechanism and a code.
Link: Hide Photos, Video and App Lock - Hide it Pro - Apps on Google Play
No, at least not yet. Basically how Hide it pro works is that it moves your data to a hidden location somewhere in the data directory in your storage. So, if you can find it you can recover all your files. They are not encrypted IIRC just that they don't appear in your gallery.