iMAME4all is a iOS universal app done by David Valdeita (Seleuco), port of MAME 0.37b5 emulator by Nicola Salmoria & TEAM for all jailbroken iOS devices (iPad HD, iPhone 4G , iPod touch and older) and it is based on GP2X, WIZ MAME4ALL 2.5 by Franxis.
It emulates arcade games supported by original MAME 0.37b5 plus some additional games from newer MAME versions.
This version emulates over 2000 different romsets.
Please, try to understand that that with that amount of games, some will run better than others and some might not even run with iMAME4all. Please, don´t email me asking for a specific game to run.
Although the performance is very good with modern devices (all games I tested on iPad run practically perfect), owners of older devices should not expect a good performance; please turn off sound because that's very helpful.
After installing, place your MAME-titled zipped roms in /var/mobile/Media/ROMs/iMAME4all/roms folder.
Please use "clrmame.dat" file included in /var/mobile/Media/ROMs/iMAME4all to convert romsets from other MAME versions to the ones used by this version, using ClrMAME Pro utility, available in next webpage:
http://mamedev.emulab.it/clrmamepro/
I am releasing everything for free, in keeping with the licensing MAME terms, which is free for non-commercial use only. This is strictly something I made because I wanted to play with it and have the skills to make it so. That said, if you are thinking on ways to support my development I suggest you to check my other free works for the community.

Version 1.9: key delay on game selection - eases game selection, added option to set Sound defaults and to choose iCade or iControlPad layout,sleep processor between inputs on game select screen, fixed multiple key presses problem and sound initialisation fixes.

http://code.google.com/p/imame4all/