Padlet is a collaborative noticeboard, which you can embed in multiple Canvas courses simultaneously. Students can add text, images, video, audio etc to the noticeboard for all to see (but don't worry there is a "moderate" function that you can enable to prevent anything untoward being published).

You can make 3 Padlets with a free account.

How to use Padlet? It is super simple, make an account here, and I have made a presentation of steps you can download (view on presenter or reading mode for animations to work).

What to use it for? I use it for sharing resources that are relevant to several courses, this prevents the need for duplication or updating of multiple pages. I only need to edit the one Padlet and it will update in all courses automatically.Here are three examples below:

1. During lockdown I collated some "Resources for Sanity":

2. For the various modules that I teach anatomy on, I have collated a list of QUB's anatomy resources:

3. I also have several Padlets dedicated to sharing Mnemonics (learning tricks) for anatomy, these are shared publicly and several thousand people have access, including other universities. Anyone can contribute to the board and so the number of mnemonics can grow through collaboration (this is of course moderated!).

p.s. If a freeware has been discontinued or made into a paid service it is worth looking at Alternativeto.net which can suggest other free alternative softwares: https://alternativeto.net/software/padlet/