If you are looking for a reliable app where you can edit your music into chiptune, you should definitely download this app called 'FamiStudio'. It's a free and simple tool to transform your music to 8-bit chiptune. Whether you are a chiptune artist, or simply a homebrewer, this app will suit you best.

The app has a lot of features you can enjoy such as having a modern DAW-style UI with piano roll, instrument, and envelope edition, note drag & drop with audio preview, DPCM sample editor, volume, fine pitch, vibrato effect tracks, and if you suddenly make a mistake, you can simply use the undo and redo feature for your convenience. There's so much more you can do with this app.