Oh man. Apple has us by the nuts. I love my iMessage. I've been on a macbook for ~10 years, but I just started working at Microsoft and thus have been spending a lot of time in Windows. Multiple times per day I think of something I want to send my wife, like a link to something I'm reading or something, and I look for the iMessage on the dock and of course there is no dock and no iMessage. I want iMessage for Windows. and Linux.
I was in exactly this same boat for a long time. I bought maybe a dozen iPhones through the years to upgrade friends and partners from Android just so I could iMessage them.
Turns out, most of iCloud is not e2e encrypted, critically, notes and pictures and contacts and backups. Apple (and by extension, US military intelligence and FBI/DHS) can read your private notes and see your nudes, and review your address book and message history. I knew I was going to need to switch eventually.
* iCloud device backup is on by default. This syncs all of your unencrypted iMessage history to Apple. It also syncs all of your conversation partners’ message histories, from their phones, to Apple. It is not e2e encrypted so it suffers from the Zoom Problem: Apple has the keys and can decrypt it, for themselves or the government via the illegal PRISM program.
* iMessage (despite being e2e) can be arbitrarily wiretapped by injecting a surveillance key because the client trusts the key list from the server blindly, with no UI notifications for the sender on key changes/amendments.
* I can’t run the client on half of my computers
* Signal works on ios/android and has desktop clients for all major platforms... and critically now supports iPads. It also has the nice property of being e2e without implicit trust in the server, although hopefully the TOFU model can be improved.
I switched. I am now signed out of iMessage on all my computers, and it’s great.
If I can do it, anyone can. I was in as far as one can go.
Apple's refusal to support Windows in any real way and have inferior experiences with iTunes etc was absolutely fine when they had best in class solutions for all your work and home needs.
But in 2020 where their computing products have left so much to be desired this whole system just starts to fall apart. I'm forced over to Windows because they don't make a machine to fit my work needs and when I'm there in Windows I'm not thinking how much I miss iMessage and I wish I'd sacrificed performance and GPUGP just for iMessage, I'm thinking maybe I should stop using iMessage because WhatsApp works great everywhere.
Then now I've switched to WhatsApp well there's one less reason I have to buy an iPhone next time.
