AdAway is an open source ad blocker for Android using the hosts file.
An ad blocker that uses the hosts file. The hosts file contains a list of mappings between hostnames and IP addresses. When an app requests an ad, that request is directed to 127.0.0.1 which does nothing. There are options to run a web server to respond to blocked hostnames and to direct requests to the IP address of your choosing. You can download hosts files from the app but it is possible to use your own and to add certain sites to the white- and black-lists.

Requires root as the hosts files is located in /system which is normally read-only.

Problem? Read this:

* If you use Chrome and still see ads on web pages, remember to disable the "data saver" or "reduced data usage" browser option
* Check your APN settings for any proxy, the proxy itself could be allowing ads. Disable the proxy.
* After you install or make any change to AdAway, you must reboot for those changes to take effect
* If you are still having issues please read and understand all the info in the wiki before asking for help here