To rename an existing preset, please follow these steps:
Go to the Timer tab (middle icon) at the bottom of the screen.
Tap the Presets tab.
Select the Preset you would like to rename.
Tap the three dots (⋯) beside the Play icon.
Select Rename from the menu.
Enter the new Preset name.
Tap Done.
Tap Save in the top-right corner to apply the changes.
Your preset name will now be updated.