Never heard of this before so ill pass onto the news right away:

GBARunner2 Git (2018/01/31) is complied. GBARunner2 ia a GBA hypervisor for DS. By default GBARunner2 will look for a "GBA" folder in the root oft the SD card, and open it. Otherwise, it will open the root of SD card. Put roms and a gba bios as "bios.bin" in the "GBA" folder or the root of your sd card. Make sure the roms are sram patched if needed. Hidden or system files and folder won't be shown, so "bios.bin" file can be hidden.

GBARunner2 Git changelog:
-Some bugfixes and improvements