I have never owned an android phone and honestly did not know that there were antivirus apps for the phone. That makes me glad that I never owned one. Are viruses much of a concern for android phones?
No, not really. The biggest concern is what everyone ignores. Apps that provide some kind of barely useful feature, but phones home and provides information about you, like phone number IMEI, your location etc.
But it's mostly a scam. Unless you really go for dodgy apps, it's all fine.