@framaservice enables the user to send pictures anonymously. You can choose to suppress them at any time (from the first viewing, 24 hours/7days/30 days/1 year after putting them on line).
Framinetestest is a server of the Minetest game, a "sandbox" game in which you construct and break up blocks to modify them and with which you can create your own educational applications.
Framemo allows you to create a table of columns where collaborators can come and leave colored notes. Like Framapad, registration is not required, and the modifications are visible and recorded in real time.