Klimmaatjes is an Android app developed by Arjen van den Broek, available for free in the Lifestyle category. It is a handy app for those who want to climb in a climbing hall but don't have a climbing buddy or their buddy is unavailable. The app offers an overview of open appointments where climbers are looking for a climbing buddy and a list of climbing halls in the Netherlands with a link to their website.

With Klimmaatjes, you can accept an open appointment, create a new appointment, set up email notifications for when someone is looking for a climbing buddy in a particular climbing hall, and follow on Twitter or Facebook to see when new appointments are added. The app provides a website overview of climbers looking for a buddy, and you can accept an appointment directly from there.

Overall, Klimmaatjes is a useful app for climbers in the Netherlands who are looking for a climbing buddy. With its easy-to-use interface and helpful features, it's worth giving a try.