AdTrap is Ad free internet for all of your devices as hardware,but I want a cheaper option.

I want to use it for devices that I can't modify.

 

more info:

http://www.getadtrap.com/

Hmmm if I were to guess... I'd guess that little box is basically a firewall that blocks traffic based on a blacklist of known advertising domains. If that is what it is, then presuming you have another computer (surely, it wouldn't need to be beefy) you could do the same thing. It is a similar concept to using the HOSTS file to block domains, however that isn't efficient once you add a large amount of entries.

The main difference likely is that the device may end up updating itself to add new domains to block... Either that or the blacklist it uses is stored somewhere on the internet already, meaning it wouldn't need to update.