Confused by versions and subscription

Sorry for the confusion.

The 5.6.6 update included a fix for Family Sharing that really only applied to the free Infuse 5 app. There were no other changes in 5.6.6, so the latest version of the standalone Infuse Pro app is 5.6.5. We typically keep both at the same version number, but in an effort to get a fix out before the App Store holiday shutdown we didn’t push an update for Infuse Pro 5.

If you want to check your Infuse Pro subscription you can do this via Settings > App Store > Apple ID > Subscriptions. If you purchased the standalone Pro app, then you won’t really need a subscription, but having a subscription would allow you to update to major releases in the future (v6, v7, etc…). A little more info on the differences between the In-App Purchases and standalone paid app can be found here.

Hope this helps!