A timer can be set in the lower left corner of the Pinboard App. Move the mouse to the corner or click on the clock button in the upper right corner.
The plus button increases the time by one minute, the double plus by ten minutes. The minus buttons work the same way backwards.
With the play button the timer will be started. It is always possible to stop the timer with the pause button and continue later. The X deletes the timer.
The students must have completed the task until the time is up. When the time is over an alarm sounds and the task is hidden. However, it is not completely gone. The text can be displayed again using the tick symbol.