Kinopio is an online app for mind mapping and more!
Source: Hello Kinopio – Kinopio
Kinopio is mindmapping software that is free for up to 150 cards. What’s really nice is that with anonymous accounts, all data is stored locally and not transmitted to a server. This is also an issue with shared devices, but if your students have their own device, then they don’t even have to sign up.
Creating an account allows maps to be open for collaboration or to be shared.