I bought the Advanced Feature Set for iOS before it changed to a subscription. Why do I need to subscribe now?

When you purchased the Advanced Feature Set (AFS), you got permanent access to the advanced features as they existed at the time of purchase. When the original AFS came out in PocketBible 2, the plan was to ask you to purchase the AFS as each new major version release came out. When PocketBible 3 came out we decided to just extend version 2 owners' AFS to version 3.

With the release of PocketBible 4, we changed the AFS on all platforms to a subscription service. Your older AFS gives you access to similar features in version 4 that you had in version 3 (and version 2 before that). But we added new features to the AFS in version 4 that you can only access with a current subscription.

If you check your subscription status on the site or in the app it will tell you that you have a "permanent subscription to the legacy feature set". That's what it's referring to. You have permanent access to the features that were in the AFS when PocketBible 3 was current. To get access to new features in version 4 and later, you need a current subscription.