There's also Ripcord https://cancel.fm/ripcord/ which is tiny, native, and works with slack. Going with electron is a simple way to get quick results so companies like it.
> Not a subscription—never expires
> Includes 1 year of free version upgrades
Are you telling me that a third-party slack client will keep working forever without updates? The "not a subscription" message here is effectively moot: this thing will stop working and you will need to pay for "another year of version upgrades".
It's not promising you to work forever without updates, but also it doesn't force you to pay if you're happy and everything still works.
Contrast this with something like sublime text: years from now you can still expect it to work normally.
What I expect is that if your app will not continue working for a long time then you should not make "lifetime license" one of your selling points unless you are prepared to offer lifetime upgrades too.