Support

Write to support@dumtek.app. Please name your device and what you did before the problem appeared.

No sound

Turn the volume up with the side buttons. Dum Tek also plays when the silent switch is on. If a Bluetooth speaker is connected, the sound goes there and arrives late; play on the device speaker or wired headphones.

I bought Dum Tek Pro and it is locked

Open Settings in the app and tap Restore. Use the same Apple Account you bought with. A purchase that waits for Ask to Buy approval unlocks once it is approved.

Refunds

Apple handles payments and refunds. Ask at reportaproblem.apple.com.

My lesson progress or rhythms are gone

Progress, settings and your own rhythms are stored on the device only. Deleting the app deletes them. Dum Tek Pro is not affected: restore it in Settings.