Scummy practices
I bought the app when it wasn’t on a subscription basis and they changed it to a subscription basis some time later, and you lose the ability to use the app completely if you don’t subscribe. When people buy an app, they expect to be able to use it indefinitely unless it’s stated upfront that’s it’s on a subscription basis. You can choose not to update the app but you shouldn’t remove people’s ability to use it. Absolutely deplorable to change it to a subscription basis unilaterally. Giving advance warning does not absolve you one bit. Other apps allow you to use the functions you paid for, just without new updates, but not this app. Completely unethical.