Passwallet is an APP created by quicket.io, a German software solutions company. You can find more information at:

https://play.google.com/store/apps/details?id=com.attidomobile.passwallet&hl=en_US

Introduced in Apple's iOS 6, Passbook's PKPass file format will quickly become the de facto standard for mobile ticketing.

Backup of Passbook passes (and syncing between devices) possible via Dropbox or Google Drive.

PassWallet is now fully integrated with Renfe (http://www.renfe.com/) in Spain.
PassWallet works with Lufthansa (see http://atti.do/pw-lufthansa for details) and other airlines that offer .pkpass files as downloads / email attachments.

List of services in use with PassWallet here: https://www.facebook.com/notes/passwallet/passwallet-supported-sites/614638531917970

RENFE, entradas.com, airberlin, Lufthansa, Kinepolis, Cleartrip, WizzAir, ticketea, Swiss International Air Lines, Nettbuss, Resorts World Manila, Hesta, Binter Canarias, Ticketfly, Virgin Australia, Рамблер, Walnut Passes & Germanwings