AdAway is a free and open-source root-only Adblocker for your Android, up and running since 2013. It uses the hosts file to block ad-serving IPs, which is why it needs root access. The app was initially available on the Play Store but was taken down later. Beware though, there are some fakes and rip offs of this app on the internet, so make sure to get it from the official links only.
uhm, nothing here atm