I've tried most of the passbook apps able to store passes in the Wallet, but it's not the same thing. When you use one of those apps, you open the wallet and then you have to find the app listed in Wallet, click on the entry, this opens another page with a link to open the app, you click on it, open the app, then inside the app look for the passbook entry. It is just a complicated launcher for the app. In the (now broken) Wallet implementation, the passbook entry was displayed directly in Wallet and was a one-click business to open it. For flight, the entries were listed at the top and the next flight was actually highlighted in a special way to make it easily accessible.