MNTNT's Albert Clock is a clock that presents the hours and minutes as simple math problems. Is it annoying or engaging? Or…. both!
In standard mode, the queries change every minute. They are completely random, so even the query for the hours change, even if the result stays the same.
You can speed up this challenge so the queries change in the fastest mode every 10 seconds.
You can also download the Albert Clock as a free mobile app.
(via Uncrate)