The necessary changes to make Instacast work on iOS 7 are so significant that it will render it incompatible with iOS 6. However, we respect that a number of users will not want to update to iOS 7, preferring the look and feel of iOS 6. Due to this, we will release Instacast 4 as a new app with iOS 7 this fall, and users who will not be upgrading to iOS 7 can continue to use Instacast 3. We will continue to update Instacast 3 over the summer while working on Instacast 4 for iOS 7. - Vemedio
I'm beginning to think paying for Instacast is going to be a yearly thing. And it's a good thing. Developers who want to make use of the latest and greatest need time and money to do so, and since Apple doesn't allow for update pricing, a new SKU is the only option.
Vemedio, if you need beta testers, gimme a ring!
It's too bad iOS 7 doesn't bring some form of upgrade pricing, as I think we're going to see a lot of apps move to new iOS 7 only SKUs.
— Patrick McCarron (@McCarron) June 18, 2013