A business idea starts simply enough: You identify a need, and then you fill it. It seems that a number of innovative entrepreneurs have identified the need to access data from mobile devices no matter where it's stored, and we're seeing an explosion of solutions designed to address that need.
Where is your data? Mine is all over the place. I have data stored locally on my PCs and tablets, and data stored on external USB hard drives, and data stored across various cloud-based services including iCloud, SkyDrive, Google Drive, Box, Dropbox, and possibly others I've forgotten about. Some of the data is redundant--duplicates of data stored elsewhere--and I do my best to consolidate the data I really need in one place, but there's still an opportunity there for a provider to give me a tool that just lets me access all of it no matter what device or platform I'm using.
Box is certainly striving to achieve such a vision. It may be viewed at face value as a cloud storage service, but the underlying philosophy that drives Box is the idea that people should be able to access and share their content from anywhere. Box is arguably closer to that goal than any other--providing access to data from Windows, Mac, iOS, Android, Windows Phone, and pretty much anything or anywhere with access to the Web. Box is also one of the first big players to develop an app for Windows 8.
I'm a huge fan of Box, and I use Box on most--if not all--of the platforms it's available on. It is my primary repository for the data I need access to. However, Box is a Box-centric solution. I only have access to the data that I have stored in the appropriate folder to be automatically synced, or that I have taken the time to manually upload to the cloud. If I need a file that I saved to the desktop of my MacBook Air while I'm away from my desk, Box won't help me.
Younity recently saved me in this exact situation. Younity scans the data on your Windows and Mac OS X PCs, and makes that data seamlessly available to your iPhone and iPad via an iOS app. Younity is limited, though, in that it only scans local drives--so data on my external drives is not indexed, and the app is strictly iOS, so it won't help Android or Windows Phone users.
There are a couple new approaches in the works that promise more ubiquitous cross-platform access to data. First, there's Documents.Me. Documents.Me is also iOS-centric. It claims to provide access to data from your computer, as well as data stored in Dropbox or Google Drive, and it will scan your email, too. It has slightly broader application than Younity, but not by much.
YouSendIt has its eyes on a bigger, "cloud-nostic future" as the company has dubbed it. YouSendIt already offers a data storage and file-sharing platform a la Box, and the company recently acquired Found Software. Found develops technologies to enable users to find and discover their files and data across devices and cloud services. Blending YouSendIt with the capabilities acquired with Found could be a big step toward a more platform-agnostic approach.
In a perfect world all of your data would be available to you no matter where you stored it, and no matter what operating system or mobile device you're trying to access it from. We're not there, but it seems there are some startups that are at least trying to keep us heading in that direction.