I think we've kinda forgotten what this thread's about: the Hyperkin Smartboy.
Hyperkin has brought real buttons and a D-pad to mobile gaming. The $50 Smartboy fits on some Android phones, and plays actual GB and GBC cartridges. It will also opens up playing Gameboy, NES, SMS and other gaming systems via emulators and find-them-yourselves ROMs.
The D-Pad and real buttons are just part of it; it also emulated games, and has a built in cart slot for GB & GBC games. The built in slot sounds cool, but why can't it play GBA games? Does this offer an advantage over a GBA w/a flashcart?