When class starts, the professor launches the app to set an attendance beacon for that particular meeting. The beacon uses the phone's Bluetooth radio to send out a unique code to nearby devices running the app.
When students arrive in class and fire up the app within range of the beacon, they'll see a check-in button on their dashboard. When they tap the button, the beacon notes what time the student checked in and sets them to present, tardy, or absent depending on their arrival time.
If the professor needs to call roll for students who didn't check in, she can also record attendance using one of the other options in the app—they're super-simple and the record automatically pushes right to your school's Populi database.
Attendance beacons in Populi's mobile apps free up class time, do away with busywork, and help make for more accurate record-keeping.