Tin

Tin is an app to ring the doorbell of your friends

It's very easy to install:

- You enter your phone number.
- Tin sends you an SMS and creates an account for you
- All your contacts in your contact list that have Tin automatically appear on the home page.

And easier to use:

Just press on a contact to send them a sound and let them know that you are at their door.

Yay!