Support
The camera doesn't see my hands
Make sure LUFTKLANG has camera access in Settings › LUFTKLANG, hold your hand about an arm's length from the phone, and give it a moment in good light.
No sound
Check the silent switch and volume. To sample sounds, LUFTKLANG also needs microphone access in Settings › LUFTKLANG.
Anything else
Write to joshfred@icloud.com — replies usually within a day or two.