It should be possible to install older versions of an app, at least the versions the user had installed in the past. This would also allow users to downgrade if a new version didn't work on their devices or all devices.
If a paid app stops working (made to stop working with an update), should not there be a refund? Is this legal?
Man, who thought screwing over the people willing to pay for their first app was a good idea? Good customers they could've brought along on the ride with their new app via a credit or something. Then hit them with in app purchases for even better service/support or something, or do nothing, which is better than what they did here.