The interface is simple, on the top, there is a drawing of the instrument. The circles are representing the holes on the instrument. Reds are covered hole, grey ones are open, orange ones are half covered. By slidig on the octave slide, you can change the target octave, this updates the note selector with the avaible notes in that octave. By tapping on a note, you can instantly see the fingering required for that note. By pressing the play button in the middle of the note selector, you can play it on the phone. The three dots button opens the options menu. This contains an instrument selector, (baroque and german style soprano recorders), you can set the note style and accentation style. There is also a language selector, only two languages are present in the moment.
Running the app is the same process as most React Native apps, install the dependencies with yarn, run the yarn start command to start the test server the yarn android command to build and install it.
I am plannig to add some new languages, some new instruments and some more features, including some polishing and styleing on the ui.