While Apple has really established quite a useful standard with its Passbook, Passbook passes can also used on Android smartphones, for instance with Attido Mobile's great PassWallet app I use a lot for my Lufthansa flights. However, there are still many airlines which are yet not offering Passbook boarding passes but often give a link to a mobile website only where the boarding pass can be accessed online. That's all good but it can be either expensive in international roaming or what happens if you don't have coverage or due to a network failure the mobile website isn't available? Well, there's a workaround I love to use and it involves Evernote!
The link to the mobile boarding passes are in most cases sent by an E-Mail and normally this mobile websites can also be accessed from a regular PC browser. By having an Evernote account and installing the Evernote Web Clipper, this page can be easily clipped to a Evernote notebook (for instance one called traveling or boarding passes).
Right after the mobile boarding pass was clipped, it's available on Evernote, doesn't matter on which device, since Evernote supports Android, iOS and Windows Phone. After synchronizing Evernote on the mobile device, the mobile boarding pass is available for use, even if the device is out of coverage, in international roaming or already in flight mode.
Having the boarding pass stored on Evernote has a further benefit: In most cases (this depends on the airline and its barcodes) it's even possible to open the barcode only which often works on gates with bar code scanners better.
This method of having the boarding pass available never failed me and it was accepted by security checks all over Europe and for boarding the aircraft.
Cheers ~ Arne