If you want to share your Chisel with another person, get them to download the Skulpt app on their own phone and sign up as a new user to create their personal account.
When the app asks them to pair the Chisel, they should follow the prompts on the app to do so.
If you then want to use the device again, just tap "Pair Device" on your app's Settings menu and re-pair it with your phone. You can do this as many times as you'd like, and with as many phones (users) as you'd like.
If the other user doesn't want to create their own profile to save their results over time, but instead just wants to borrow your device to take a measurement or two, then tap the "Guest Mode" option on your app, so your guest can measure themselves without storing their data to your app.