Can more than one person use the Spirolink device/app?

Yes you can. You can add multiple users to your account by going to the settings tab at the bottom right hand corner > click "manage users" > Click on the (+) icon to add user > Add as many users as you would like.

To filter between the users, you will go to the home tab and at the top of the screen where your name is located and there will be a drop down icon that will allow you to select which user will be tested and record stored.