Zulip hits all of these if the "view edit history" feature fulfills #1 for you.

There's also an iOS app.

https://github.com/zulip

Wow ok, that's pretty great.

What does the iPhone have to do with it?

As an OpenSource developer, I am fine with paying the one time $25 fee for Android, but not the $1500 computer and $100/year to make my app available on the app store

You can develop for iOS without actually owning Apple hardware.

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...

[1] https://www.macincloud.com/

1) that’s ridiculous.

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.