Two years ago I bought Purity 1.2 and I have been using it with Garageband. Two weeks ago I bought Logic Express 9 and Purity 1.2 is not working any more. When I tried the 1.2.4 Demo version it worked. How can I upgrade the application?
Nowadays, the latest version of the application is Purity 1.2.7. Its price is around $49 and you can purchase it from the official web page. Also, I suggest you contact the developer to see if there is any discount available. If you have any issues using the software, you can check the official user guide.