We didn't go into the church but went to the chapel to see the famous frescoes by Masaccio and Masolino. The audio guide is presented on a tablet so that the narrator can zoom into the sections that are being described. I believe this is the first time that I've seen this done before. It's totally awesome because the frescoes are up high and you wouldn't get to see the level of detail present on the tablet.
Entrance fee is Eur6. In addition to the chapel you get to see the gardens and they had a couple of rooms with a few art pieces. The chapel is the main attraction. One hour is about the right amount of time for this attraction.