I immediately subscribed to ultra. The reason is I think there is not enough active Lemmy users to sustain app developments with just one time purchase right now. I used sync for reddit a lot in the past (bought pro and dev versions, but not subscription version), but for the Lemmy version, I think it would be hard for the dev to continue working on the Lemmy version indefinitely (I think the dev is working on this full time?) without some sort of recurring income. I don't want this app to die an early death so I'll do what I can to support it, including paying for the relatively small $17/year subscription.