Vpin is a free Android app developed by MBDEVS AA that allows you to pin virtual notes (vpins) anywhere you want, as long as GPS signal is available. The app lets you add vpins without actually being present at the location.

Vpins can be viewed by users who have vpins or marked the spot as a location of interest. Each vpin can be tagged private, making it easy to check for new vpins at its location. Additionally, the app has an offline mode, so that vpins can be saved and uploaded later when an internet connection is available.

The Vpin app also has a messaging system, allowing users to message each other. To use Vpin, the app requires access to your device's location data, an internet connection, and the ability to modify/delete SD card contents to allow the Google Maps API to cache map tile data.

Overall, Vpin is a useful app that allows users to leave virtual notes at locations of interest. The app is easy to use and has a convenient offline mode feature. The messaging system is a nice addition, adding to the app's overall functionality.