Cloud Appreciation Society
The society for people who love the sky
https://cloudappreciationsociety.org/
They have a free CloudSpotter app.
"Our CloudSpotter app will teach you how to spot 58 different cloud formations and optical effects, from the common ones like Cumulus clouds and rainbows to rare ones like the fleeting fluctus cloud or the hard to spot circumzenithal arc."
If you have a fediverse account, you can quote this note from your own instance. Search https://mastodon.social/users/appassionato/statuses/115766096341341612 on your instance and quote it. (Note that quoting is not supported in Mastodon.)

