2. AVG Antivirus
Price: Free; US$9.99 for pro version

Besides the usual scanning of apps, files and media in real-time and protection against phishing attacks, the AVG Antivirus app eliminates tasks that slow down one's device.

Users can also find their lost or stolen smartphones via the app which is integrated with Google Maps, or leave a message with a return address for people who find the phones.

For US$9.99, the AVG Antivirus Pro adds battery and storage optimization, secures apps from being accessed by others, and lets you back up all apps to the user's SD card.

3. Seal App Locker
Price: US$2.54

From Gmail to WhatsApp, Seal can be used to individually lock any app on your phone with a complex or numeric password, or a pattern.

Apps can also be arranged into profiles to be locked and unlocked as a group, and each app can be enabled or disabled easily from the Seal interface by tapping the radio button.

4. GadgetTrak Mobile Security
Price: US$19.95/year

For those who are more worried about lost or stolen devices than malware scanning, this app uses GPS, Wi-Fi positioning and cell tower triangulation to track a phone's exact location. In case of theft, an alarm can be activated remotely even if the device is on silent mode.

The software is also tamper-proof and users will be alerted to unauthorized SIM changes or new number assignment on the device.

5. NQ Mobile Security and Antivirus
Price: Free; US$19.99/year for premium version

NQ's privacy protection monitors apps that access your private data without permission, which is handy with the proliferation of rogue apps . Its traffic monitoring function also ensures you do not go over your data plan's limits, and lets you rank apps by data consumption.

The premium version comes with additional automatic virus database updates, online banking protection, and the ability to lock and wipe data if the phone is lost or stolen.