Planpop is a free iPhone app developed by SEVENDAYS, Inc. that allows users to share their plans with friends. The app is designed to help friends organize their schedules and enjoy events together.

With Planpop, users can create customized plans by adding date and time, location, pictures, videos, alerts, and URLs. Plans can be shared in-app, from contacts, or posted publicly. Users can also keep their plans private.

The Home Tab allows users to check out their friends' plans, while the Calendar feature enables them to add plans to their calendar or join their friends' plans with one tap. The Chat feature lets users coordinate with friends, make groups, and share plans directly in chat.

Overall, Planpop is an excellent app for people who want to stay on top of their schedules and enjoy events together with friends. The app is user-friendly, and its features are well-designed and easy to use. However, it would be great if the developer could add more subcategories to the app to make it easier for users to find specific types of events.

Please note that feedback can be sent to or chat with @Teamplanpop in the app.