Interface builder will generate default user interface, which can be edited later. You can also create user interface from scratch using web technologies (HTML, javascript).
Free users may create standalone applications, but only premium users can protect application source code.
Premium users can use skype or email to get support. Guaranteed response within two working days. (You will get instructions in personal cabinet).
Premium users can manage customers licenses through web interface. Licenses for BAS scripts may be limited in time. Premium developer can stop user license manually or prolong it for specific user. Each license can be used only on limited machine number. This is done in order to protect script from unlicensed copying. Premium users can change machines number individually for each license.
Premium users update script instantly on all customers machines through web interface.
Useful if you want change BAS and get actual source code.