How to block images in android app In my country data is really expensive, I find my self spending almost $50 every 2weeks, which is a lot of money. 
I've been wondering if there's a way to disable images in android apps, This would be very useful, and save a lot of data. 

I've a rooted phone 
5.1 lollipop
You cannot in general.  Images are arbitrary data; they come from different sources, in different formats, over varying protocols, with or without encryption.

The best you could do is to figure out what domains the images are coming from and block those domains.  I use Shark to sniff app traffic and discover the domains.  For example, i.stack.imgur.com hosts the images uploaded for questions and answers on the Stack Exchange network.  There are various apps to do the blocking, or you could manually edit the hosts file.

Browsers like Opera can also compress images when browsing (supposedly Chrome can now as well), and might even have options to not load them at all.