While not an antivirus app, Fyde Mobile Security & Access is still worth considering because of its focus on identity protection and privacy controls. This is especially important because these days malicious apps, websites, and malware are more interested in stealing your data than corrupting your hardware.
Additionally, not only is the app free, it also aims to put as little stress on your battery as possible, which is positive as some security solutions such as VPN's can drain batteries fast.
The app itself is simple and easy to set up, and once running it means you have protection against rogue wifi networks, as well as phishing websites, and more.
No data is collected on you by Fyde itself, but you can choose to send anonymous data of any attacks registered to the Fyde community as part of their crowd-sourced intelligence improvements.
Overall, this is a modest app that doesn't over-promise but delivers on what it does.