How to validate bus tickets in Florence

[traveling gal]

My husband and I have each loaded the at-bus-it app on our phones and have each purchased a carnet of 10 tickets for Florence. Can you please describe how we validate from our phone when we get on the bus? The phone app says 10 tickets available, tap to activate. We're just not sure where or how to "tap". Also will the number shown as available decrease after each tap?
Thank you for any information. We enjoy your Discover Tuscany posts and find the site very helpful.

 

[Lourdes]

Yes, you should click on the "tap to activate" link and then it should show time activated, you show that in case you are asked for a ticket by a controller on the bus.
The number should decrease by a ticket every time you use it, so it should be easy to keep track of how many you have you can still use.

Hope all goes will during your time in Florence! Let us know if you have any questions