The password or pattern lock on your smart phone can only do so much to protect your privacy. But when you let someone use your phone, there's always that risk of them reading your messages, viewing your pictures or files that you'd not want them to, and of course that inevitable fraping that leaves everyone questioning your
sexuality. There are some apps in Google Play Store which can help you out in these cases.
It's a free app that lets you lock other apps on your smarty. You can use the password or pattern lock, and there's a random keyboard option and pattern invisibility option to prevent peepers from gaining access. All you have to do is select the apps you'd like to lock and adjust the password/pattern.
You can use this app to lock all system and third-party applications, as well as services such as Wi-Fi or Mobile Data. It also allows you to lock the installing or uninstalling of any application from your phone, so that others can't uninstall AppLock itself to invade your privacy. It also has a time lock and a location lock feature, meaning that you can lock/unlock all selected apps at a particular location only or at a particular time.
Another great feature is the fake cover option, which can be used to confuse your invaders. Moreover, you may use it to hide photos and videos to a secure vault, though it is advisable to use a different app for that. The only downside is that the app is deactivated automatically in some phones after a reboot, depending on the phone's own settings.
HIDE IT PRO
This is another free application to hide your files, including pictures and videos that you'd not like others to view. The app disguises itself using the icon of an audio manager (customisable to a currency converter as well), which is completely functional to make the disguise more authentic. You need to long press (duration customisable) a particular button to remove the façade. You then have to punch in a password or pin code to finally access your files. As complicated as the double protection sounds, it gets easier once you know how to use it. You can hide your files in the app's vault and only you can access those.
Using this application, you can hide your messages and even entire apps too, but you'd need additional plug-ins for that. It also disappears from the recently used applications log. Additionally, if you get caught while hiding a file, you can punch in a preset fake pin, and the vault will appear empty to others. The app is still in its development phase, so it can only get better in the future.
There are other great apps with high ratings like the two discussed, but these two are highly commendable. A combination of the two apps to prevent the invasion of your privacy is impeccable.