HOW TO REMOVE ADS FROM FREE ANDROID APPS :
Google aren't currently offering many ad-blocking apps in the Play store, and this is probably because ads are used to make money for publsihers, so you need to go off piste a little in order to banish ads for good.
First you need to root your phone. By rooting your phone you change the user permissions which allow you to do anything with any file or folder. Although it gives many benefits, we're interested in the ability to upload any Android apps, including unofficial apps that you won't find in the Google play store, such as ad-blocking apps.
As with many of the best Android hacks, you may need a technical friend to help you, but don't worry because it's not too tough if they give you a hand.
Then install the app, download a new host file with it (you can see the command above in the open app), and then restart your phone.
Now all of the free apps that you love to use won't show you any apps which bother you, period.