The best mame for arm is mame4droid (139.1 u romset) if works in 1000 mhz/dual- 700 Mg ram android tablet. (with more 8000 roms).
In android are 37b5 for low spec. smartphones and 139 for medium/premium.
In raspberry are 37b5 for raspberry Pi A/B/B+/2 B. I think is time for 139 for Raspberry 2 B.