Tumblr announced they were gonna integrate with ActivityPub years ago. It’s been silence on the topic since then, hopefully this move to Wordpress is a step towards joining the Fediverse.

The link to the original TechCrunch article doesn’t seem to be working, but here’s a mirror on Slashdot: https://m.slashdot.org/story/407458

Signal is open source. Go read the source or a write up describing what it does.

Signal doesn’t store your encryption key in the cloud and yet it supports e2ee messaging on multiple devices including desktop.

Telegram is not private messaging.

You’re not gonna find a self hosted solution as good as iCloud Photos, at least not yet. As a stop gap you can turn on advanced data protection on iCloud to significantly improve your privacy.