Russian coder lsd_blottr has made a couple of alterations to the stock firmware of the Letcool N350JP and consequently the device now has correct button mappings in the GBA and SNES emulators. Previously the shoulder buttons were mapped to volume control and to use shoulders in game you had to use face buttons instead. Also in the changelog is that the device now automatically returns to LCD mode once the TV cable is unplugged.
The frontend has also been skinned with new artwork, which personally I think looks rather nice. Here’s the boot screen and the main menu: