Install Oops! AppLock(https://play.google.com/store/apps/details?id=com.keybotivated.applock) from Google playstore on your Android phone. After installing it on your phone, don’t be surprised when what you see is a note taking apps (k-Note), Is Oops! Apps disguising as a note taking app

=> How To Lock Apps With Oops! AppLock

To lock application , swipe the app from unlocked list to left as shown bellow, it might not show immediately in the lock tab, just pull down the list to refresh.

So, whenever you are opening a locked app, it will not be using a pin or a pattern lock. Instead it will be using a combination on the volume control buttons to gain access to the locked apps.

=> How To Change Volume Lock Pattern

To change the volume lock pattern,

Note : The default pattern is Up,Up,Up

– Open the app Settings at the top right corner of the app.

– Tap on Change Key Pattern.

– Now select how many combination you will like your pattern to be, either two,three,four or five.

– Now enter the volume pattern. Mind you, can combine up and down volume just as you wish, take for example, you can use Up,Up,Down pattern.

– Then re-confirm the volume button pattern and if it matches, it will be set as your new unlock pattern.

Note : Whenever you entered a wrong pattern while unlocking an app, just tap on the screen and retry!

Recommended : How To Easily Format Android Phones

Another interesting features in Oops! AppLock is that you can change the background of each app lockscreen, you can leave it to the None (Which fake a crash of the app) or Black or Custom (Where you can upload a picture ). To change the background of a app, swipe app to the left and choose one of the 3 options.

Tip : You can fake a screenshot of the app and set it as a lock screen image, this will fool anyone who is trying to gain unauthorized access. Cool right?

=> How To Unlock Apps With Oops! Applock

To unlock application , swipe the app from locked list to right, it might not show immediately in the unlock tab, just pull down the list to refresh.

Let me know your view about Oops! AppLock.

Sources : http://www.techlug.com/2014/12/lock-android-apps-with-volume-button.html

hmm u try