Security Defender(Antivirus, Booster, App Lock, Privacy Clean, WiFi Security) is absolutely free.
★ A World Class Antivirus Engine - Virus Cleaner
Security Defender provides a continuously growing, cloud-based anti virus database which provides you with secure Android experience without any threats (malware, Trojans or any extortion viruses).The antivirus engine effectively scans and kills all Android viruses on your internal device storage and SD cards.
★ App Lock - Privacy Protection with stylish themes
You can secure sensitive apps. This password is different from your phone unlock password, which gives your device an extra level of security. Unlock your private apps by fingerprint, pattern or PIN.
Security Defender's Key Features
A World-Class Antivirus - Virus Cleaner and mobile threats remover
Phone Booster - Boost mobile to get it running faster and smoother
Junk Clean - Scanning both internal and external storage (SD card)
App Lock - Sensitive application locker
WiFi Security - WiFi speed test and detect WiFi Spy
Professional, Fast, Easy, Space-Saving and Efficient