I hope you get some success with your app. Speaking of, how is it doing? I keep hearing about mac AppStore not being very good but how is your experience? Do you get downloads and revenue?
One suggestion -- the trial is difficult to use if I have a long file, because it won't let me select a file that is longer than 5 min. Maybe let me pick a longer file but only transcribe the first 5 minutes? Most people aren't going to edit their files to accommodate your trial mode.