I've long been a proponent of text files for your recipes on your electrical devices. It's not as pretty but is compact, portable and DEVICE INDEPENDENT.
Text files can be read on iOS, Android, Win, some e-readers and all the primary desktop computer devices. Even my mp3 player can manage plain text.
With the system tools and a little self imposed organization, they're easy to search too.
But now to the Cloud.
One of the major hassles of multiplel computer systems is sharing and synchronizing the content. You might be emailing yourself recipes to read them off your phone, or shuttling SD cards around.
Cloud basically means storing data off the device but accessible via the internet. There are a number of Cloud services out there. Amazon is starting one, but Dropbox is one of the earlier ones and is the service that integrates with an Android app that I'll discuss here.
First, you need a Dropbox account. If you don't already have one, you can set up a free account with a 2gb. This installs an application (compatible with windows, apple, linux, android) that synchronizes files within a certain folder to the Dropbox server. Once you have an account, you can install Dropbox on your other devices. This gives you seamless access to the same files on all your devices. And as long as you have internet connectivity, they stay updated.
If you create your Dropbox account from a referall, both you and the referrer get some extra storage space so PM me if you want to create a Dropbox account. Or skip me and go to https://www.dropbox.com You'll be giving them your email address as part of the free setup.
Further, you can access your Dropbox account through a web interface on computers that don't have your Dropbox account installed on them. So at a friends house, you can still get access to your recipes or other files. But they won't have continued access once you log out.
All right, that's a cool system in it's own right so where does the Android app come into it? Most portable devices supply no file browser. You might download one of your own (a good idea) or install Dropbox on it's (also a good idea) but many people never need to use a file manager on their devices.
Epistle is an Android note taker/text editor that automatically syncs to a Notes directory in your Dropbox account. https://market.android.com/details?id=com.kooklab.epistle
There is no need for you to manage files manually. This is handy for to-do lists, shopping lists and other info you want access to on multiple computing systems.
And it also will do the job for a single source recipe archive (within storage limits) across your multiple devices as well.
I've not tested it with nested directories yet.
I expect there will be further refinements to this concept and probably even full blown Cloud recipe systems eventually. But this is a good solution available now, that works cleanly with my text recipe files now and preserves my future portability. It requires no conversion because I'm already all text.
I'm not tied to proprietary formats.
Now, I do have some content in other formats, like PDF and such. But those too are easily synced with Dropbox and PDF readers are available in any computer system, smart phone or tablet.