I've tried a few, the best one was pingo (https://css-ig.net/pingo). Pingo -s9 gives better results than oxipng with Zopfli, while being usually two order of magnitudes faster. It's also faster than "regular" oxipng while being better. I can usually shave of 15%/20% of the size of png files I encounter. One thing I didn't check is that you might pay that in decoding time, I've never seen anybody talking about that... - Source: Hacker News / about 2 years ago

Pinga, GUI for Pingo (https://css-ig.net/pingo) for lossless photo compression while keeping the metadata. Source: almost 3 years ago

Check out https://voicethread.com/. Source: about 1 year ago

Well, I teach primarily first-year-writing courses and discussion is a significant component of the course. But, rather than thinking generically about discussion, I prep assignments based on goals and outcomes. I choose tools and formats based on what I’m trying to accomplish and rarely does a traditional discussion board assignment work. Essentially, different tech tools allow me to create specific learning... Source: almost 2 years ago

Do you want Canvas-specific features, or would you be okay with tools you could provide a link to in Canvas? For example, I have had success with PearDeck (read the privacy agreement carefully so that you understand how Google will/may use user data) and a colleague of mine has created really cool assignments with VoiceThread. Source: about 2 years ago