When you encounter a pokemon on your pokehunt, tap the notification and type the name of the pokemon. This information will be available for everyone else to use.
If you come across a marker where there is no pokemon, tap on the marker and report it. After enough reports, the marker will disappear from the database.
Stop the service once you're done playing Pokemon Go to clear the notification.
App icon made by Freepik from www.flaticon.com
Pokeball by Stéphanie Leroy from the Noun Project