Me? Never again.

I used to... like some app, paid for a "PRO" version to get additonal features. Everything was ok.

Then 6 months went by, and they added a cloud feature, to upload some stuff and configs and sync between devices, and it turned from one time payment to a subscription plan. Then built-in features got moved into the cloud, and previously working stuff didn't work without subscriptions anymore. Then they added ads. PRO has maybe 2 more features than a free version and no nag screen at the start, and that's it.