A free app for Android, by Wallame Ltd.
WallaMe – Augmented Reality
WallaMe is a fun app that lets you hide messages in the real world using augmented reality. You can use it to create an Augmented Reality wall in a few minutes, so you can leave a message in a place where everyone can see it.
You can also take photos of the wall you want to leave a message on, and then use the app to share the photo and the location with your friends. They will be able to view your AR wall and read the message you left.
The app is also fun because it includes a lot of stickers that you can use to decorate it.
If you want to create a public AR wall, you can also do that. You can add the photo you want to share and the location, and then publish the photo and location so everyone passing by the location can see the photo and message through the use of this application.