No erasing edit history
Open source
Self hostable
The iPhone means the last two won’t happen and people who set their clients to auto load remote images means the first one won’t.
There's also an iOS app.
I develop an app and use MacinCloud[1] to build the iOS version. Costs $1/hour on demand. The hardest part was getting a two-factor enabled apple id. I actually had to borrow a physical iPhone just to activate the two-factor authentication. Once it is activated, you can get away without an iPhone again.
Just saying that it is possible without the $1500 hardware. It still sucks that Apple makes one jump through all these hoops...
2) you still have to pay $100 a year to do push notifications and the effect is almost no one maintains the push severs for open source apps because the people running the actual servers aren’t allowed to.