Upgrade v5 to v6

Textastic 6 is the first paid upgrade since version 1.0 was released in 2010. Implementing split screen multitasking, making the app universal and supporting iPad Pro required a rewrite of large parts of the app. Charging for Textastic 6 allows me to continue to dedicate resources to improving it.

Let me explain why I didn't offer a discount for existing users:

The only reasonable way to offer upgrade discounts would have been to leave the previous versions of Textastic on the App Store and offer up to three upgrade bundles (iPad -> Universal, iPhone -> Universal, maybe iPhone+iPad -> Universal). Using "Complete my bundle", existing customer would have been able to get a discount.

While this may work if you know how the App Store works, I think it's too confusing - especially if you are a new customer who sees three versions of the app and up to three upgrade bundles when browsing the App Store. I'm sure people would buy the wrong bundle or wrong app or wouldn't buy at all because it's not easy to understand. Also, bundles were not really meant to be used like this by Apple. So I decided against doing that. I guess it's now too late anyway since many people already bought the new app at full price and I do not want to irritate anyone further.