80% of the app is the same. It's not like he spent years creating a new app from scratch. I'm not saying he doesn't deserve compensation but I feel like he's being a bit gougey in this situation.
Prices are ridiculous, especially for returning users. The Lemmy app is basically the Reddit app. You can't convince me that at least 85% of the code was re-used from it. If you used the code from the app I already paid for (twice) I feel like I should get a discount.
And it sucks unless you want a feature phone.