I've been using the free Avast Mobile Security and Antivirus with Firefox for Android for almost two months. It's easy to use and i trust it. The only thing i don't like is the many notifications, but that may be related to settings. Make sure you disable any existing security apps where you are ready to install the "replacement" app. Your first line of defense should be to keep All of your apps up to date. Safe surfing!

Hello Avast does not protect Firefox browser in phones. Check the Web Shield to see which browser avast protects