They release a new major version every X years and stop supporting the old one. The old one will keep working until it doesn't. If you want the new one, you buy it and upgrade.
Airmail used to do this and I believe Tweetbot still does it.
Airmail messed it up and I stopped using it altogether after years. I talked to friends that I know used it and they also moved away from it when they messed it up.
It's similar to how Jet Brains does it.
They moved to a subscription model with Tweetbot 6. At least Tapbots is not being dicks:
- Twitter makes them pay for the API 2.0
- The Tweetbot subscription is shared across the family
The former means I get access to Twitter without ads, kind of like the oft asked "I'd pay to have no ads", and I get a usable UI in the package.
The latter is so rare I didn't know this was even possible until that last update.
If there's anything missing, they'll migrate. If not, they don't need it or don't care about it.
That's what I do every year when I have to renew my JetBrain products.
Do I need it? Will I actively use it? Is it just worth keeping the current version?
Someone else mentioned that they're being charged on the new API they're being forced to move to. Seems like it's needed.
However, I'm curious what other apps will do and if that will cover desktop and mobile apps.
We'll see.