[palosanto]

1) If you tap a beat with your finger, the interval between taps will be measured and the metronome will set a tempo to match that.
2) Set the first to 60, tap + to add a new tempo, adjust that to 90. Now if you tap the dropdown you will see you have both 60 and 90.
3) Tapping + creates a new tempo, and the default tempo is 10, so that's why it shows up as 10. Remember tapping + does not save the current tempo as a new tempo, it adds a new tempo to the list which you then have to adjust. Think of the dropdown as selecting the current tempo in the list which you can then modify. You don't adjust tempos and then add them to the list - you add tempos to the list and then adjust them to match what you need.

Mike

1) Perhaps is not sufficiently explained in the manual (pg 88), it seems to read that you click the button to set the current tempo shown in the slider,  I didn't realize that you actually tap on it several times to approximate the required tempo, however, now that I understand, it's a great feature!  .   I have a SoundBrenner metronome watch and it has also this feature.
2-3) My confusion was thinking that you tap on the + to save the tempo not before setting it. Again it could use a bit more description in the manual (pg. 92)

Great, thanks Mike!