ISO to CHD

[Zero_X]

No not really! I used a tool called chdman that MAME offer for free on their website. I just read the instructions, placed the games I wanted to convert into a folder, and ran the program (either CD or DVD depending on the system that the game was for) and it converted each of them into .CHD. each conversion took less than a minute on my device and saved anywhere between 30 and 80% of the disk space. :]

There's an app called ChDroid, I think it's new, I'd go try it now.