The original iMazing license model was to charge a one time fee for X duration of updates. When a next major version released, you would pay to upgrade (at a reduced cost if you already paid for a previous version).
So, for the local app, there should be a fee. The fee includes updates under 1.X.X. If they want updates to 2.0, then they need to pay an upgrade fee (this covers your reoccurring development). (Also you should have a recovery mechanism if they want to install it on a new computer and invalidate the old one).
Then if you add a cloud component, you charge separately for the cloud features. Using the software sync, or in browser, or x, y, z...
I don't mind paying for software that does its job, because good software rarely exists and I want the devs to keep making it. But if the software has no way to purchase it outright, then it is less ethical. At least allow payments for X amount of updates, so I can always run 1.5.2 as long as I need to. That is stability needed to trust the software.
I like this idea. What I might do is sell a license to the software for + a year of updates for 25$ or so. People on the subscription get updates free of charge for the duration of their subscription. People on the one time purchase can get the cloud features for a discount (and people on the subscription can get lifetime access for a low fee)
So maybe local: 25$, cloud: 30$/y, local -> cloud: 10$, cloud -> local: 5$
Need to play with numbers but good food for thought.
This is exactly how most software did it before the internet made subscriptions a technically viable thing. Huge companies managed to be built on this method.
So, for the local app, there should be a fee. The fee includes updates under 1.X.X. If they want updates to 2.0, then they need to pay an upgrade fee (this covers your reoccurring development). (Also you should have a recovery mechanism if they want to install it on a new computer and invalidate the old one).
Then if you add a cloud component, you charge separately for the cloud features. Using the software sync, or in browser, or x, y, z...
I don't mind paying for software that does its job, because good software rarely exists and I want the devs to keep making it. But if the software has no way to purchase it outright, then it is less ethical. At least allow payments for X amount of updates, so I can always run 1.5.2 as long as I need to. That is stability needed to trust the software.