Great on Mac, buggy on ipad
Response from developer
Thank you for reporting this problem. The .syx File appearing in the System Exclusive View's selection list is a bug. You cannot open a .syx file. This application can only open text files(.txt). If you want to send messages in the System Exclusive View, save it to a text file, then move it to the 「Pocket MIDI」 folder in the 「Files」. You will then be able to select it from the list. This bug will be fixed in the next version.