OBSERVER is a free Android app developed by OBSERVER Inc. that allows users to share photos of their local weather conditions. With OBSERVER, users can upload photos of the weather in their area and receive labels from other users. In addition, users can view weather photos from around the world and attach labels to those photos as well. The app also offers various activities that users can participate in and receive rewards for. These rewards can be easily withdrawn as tokens.

The app's interface is straightforward and easy to navigate, making it simple to upload and browse weather photos. Overall, OBSERVER is a great app for those who enjoy sharing weather photos and want to participate in a community of weather enthusiasts.