As you probably remember, Apple started requiring apps to have an in-app purchase option for individual sales and for subscriptions. Red Foundry has an app that managed to get caught up by the new rule because of how their app works.
VIZ, which was free before, is a development tool. It lets developers run an app on iOS and test the app with interactive content that the devs can download from elsewhere. This puts VIZ in conflict with the new rules. In order to comply with the rules, Red Foundry will now charge a $.99 monthly subscription.
Yes, Red Foundry is being forced to add a subscription to a free app. Bizarre, I know, but it's not their fault. On the upside, devs will now be able to test subscription features from inside VIZ.