Enriched wisps are found while training the divination skill. These wisps provide double the experience gained while collecting them as well as while being deposited.
These wisps spawn every third of an hour, based on the time of the RuneScape servers. The time they last is based on the number of people collecting from it. More people cause the wisp to remain for longer periods of time, allowing you to gain more experience.
This timer runs based on server time, guaranteeing that you never miss a chance at the enriched wisps. With audio enabled, you can leave the tab open but minimized in the background and still receive voice notifications of when the timer reaches 10, 5, 3, and 1 minute!
Clicking start will grab RuneScape's server time and begin a countdown. When this timer runs out, it'll automatically notify you and restart.