I haven't heard of any app calls but I'm sure they're out there. Looks like there are a few mouth calls as well. If you watch some videos on it, you'll definitely want to try is. I think a treestand about 5-6' off the ground and a quiet 22 would be a pretty fun setupI do have a bunch of subsonic 22lr. I guess I should pick up a coon squal, have you heard of any decent app calls for raccoons?