The program seems to work fine, it doesn't requires to use just WAVs like almost any other sound modding tool. I'm only using it to change SFX/Voices btw, so maybe that's what I haven't run into any problem.
Keep it up!
Top screen is 1024x256 but it uses 960x240
Bottom screen is 512x256 on static, 1024x256 if it's animated. Some parts of the image aren't seen on 3DS.
Check the file I've attached.
I suggest using Photoshop (or GIMP)