Sorry. The version of nanoloop I use does not work on the Super Game Boy, and even with a backlight in gameboys it is not exactly easy on the eyes at times. For me it is easier to stare at a tv for hours than a tiny, low resolution screen with bad contrast (although they are better now than when they were manufactured). The demo version can be used on emus and flash carts, but it is not complete, so I cannot create full songs or save with it.
There is truth to "nanoloop is so great on the gb" but there is more to it than that, and I prefer it not to be stationary. Although you can get close to the sound you want with something close, such as an emu or SGB or another gameboy, not all of them sound exactly the same, so it helps to compose amd play on the same device, and mine are each modded in different ways which can also affect the sound. I also use nanoloop for Android, which is a different thing entirely, yet based on the original version.