Tuner is available for both the Spark app and the Spark amp. To access the tuner on the Spark amp, please see How to use tuner on Spark amp.
Select Tuner. (If you don't see the option, please update your Spark app to the latest version.)
The Tuner will react to your guitar input and mute your guitar sound automatically. The graphic will show you whether your string’s pitch is too high or too low, and you may tune your guitar accordingly.
Tap the close icon on the top right to exit the Tuner page. Alternatively, you can deactivate the tuner by pressing the Tuner button or any of the Hardware Preset buttons on the Spark amp to exit Tuner mode.