As a professional photographer I have been using pass since its inception. I have used many other services and find pass to be the easiest least time consuming service for professionals.
As an app it has never let me down, and has always worked well. I cannot speak for iPad air users but to address the one review that claims they lost images, this app cannot erase images! This app is a window to an online service.
I have never once had a problem with this piece of software not working for a customer.
Just a note, I do not work for PASS nor am I sponsored by pass.
Studio Foto about Pass Classic, v2.2