Sonic generates a sine wave tone with easy precise control over the frequency. Swipe your finger up and down anywhere on the screen to raise or lower the tone frequency. Swipe slowly for small frequency adjustments and quickly for larger adjustments. 

Sonic features you will love:
  • Generate tones from 0 Hz to Ultrasonic 25 kHz.
  • Use other apps with Sonic in the background.
  • Broadcast Sonic to bluetooth and Airplay speakers.
  • Eject moisture from the device speaker cavity.
  • Control tone from your Apple Watch.

For advanced users, Sonic provides selection of 5 different waveforms: Sine, Triangle, Sawtooth, Square and White Noise. This feature is available as an in-app Purchase.

https://apps.apple.com/us/app/sonic/id986999895