One tool, several classroom activities
A spinner wheel is flexible enough to support several different classroom activities without needing a separate app for each one. The same interface that picks a random student can just as easily randomize a review-game category, a reward drawing, or a group assignment — the entries just change depending on the activity.
Because the design is high-contrast and the labels are large, it holds up well projected on a classroom screen or interactive whiteboard, which matters more for a tool used in front of a full room than one used on a single device.