Clean Master

Description
The World's Most Trusted Android Optimizer, Speed Booster and Free Anti-Virus app, Clean Master Helps Accelerate and Clean Up Over 400 Million Phones! It Also Provides Real-time Protection With the #1 Antivirus Engine, and Secures Your Private Data With the AppLock Function.
Have you ever encounter the following problems?
Your device has become laggy and freezes all the time
You don't have enough space to take more pictures or install apps
Your battery has started draining quicker than ever
Your device overheats and needs to cool down
You want to lock your photos, gallery and messages from prying eyes and nosy friends