Working on Dipla, I mini social network for local communities, you can post things and comment anonymously, posts stays the area for some days. We believe this could be used to warn about things around, or say some critics for shy people ...

Android : https://play.google.com/store/apps/details?id=io.dipla.app iOS : https://apps.apple.com/us/app/dipla/id1501533164

Enjoy !