Carat is a camera application made with Flutter, supporting both Android and iOS.
Various creators create camera filters, and other users can use them.

Currently, Carat supports only color filters, and users can take pictures or record videos with them.
Other types of filters are soon to be added, and camera features will further be extended.

In development perspective, the current camera plugin itself provides very basic functionalities.
In order to support using color filters (and improve some stability issues regarding camera plugin), a lot of plugin code had to be amended.

Nonetheless, using Flutter was way better and faster to successfully develop both Android and iOS apps, rather than starting from Android and iOS natives from the bottom.