Pop Up Ads On Phone

[Goofy]

I've just started getting some irritating - and loud - pop up ads on my phone (HTC). No idea why or where they come from. And most importantly how to stop them! A couple from Waze (I think), and a couple from some co. wanting me to do something with photographs. Any idea how I can get rid of them?
I've recently downloaded a couple of apps. One is a compass and the other Avast mobile. Could either of these be the roblem?
Thanks

[Baldric]

Had the same problem until I downloaded 'Adblock Plus' for Android

Make sure you pick the right version and don't use it on AB

[Goofy]

I'll try that, thanks Baldric

[Goofy]

I think adblock willstop me from getting more, but it doesn't seem to help with the ones that I've already got. Still popping up all the time.

[fender62]

do a factory reset of the phone, backup contacts first

[Goofy]

I'll try that. Thanks