When you select an unequal temperament from the list of temperaments, the selected temperament is applied to the current tuning. These deviations from equal temperament are sometimes called "historical temperaments" because they are derived from tuning methods that were common in older musical periods, although some modern work also has been done in this area. An unequal temperament is defined by 12 offsets that are repeated in every octave. If a temperament is already applied to the current tuning, a "Cancel temperament" button will appear in the lower right. Tapping on "Cancel temperament" will remove the unequal temperament from the current tuning (but not from your device) and return the current tuning to equal temperament.

You can also permanently delete any existing temperament from the list of temperaments in your device by swiping fron right to left across the name of the temperament in the list.

In addition to selecting a temperament, you also have the option to normalize unequal temperaments in two ways. Tap on the Options button in the lower left for details on these normalization options.