Dropbox is releasing new APIs for iOS and Android that simplify integrating the cloud service into apps. Although it technically doesn't add any new file sync features that weren't already available to developers, the new API means that including Dropbox in apps will be much easier. Simpler integration could drive adoption and help make what has already been a popular, common cloud storage solution the de-facto standard — especially for cross-platform apps.

Dropbox is in a slow and steady process of redefining itself as more than simply a cloud file system — a space that is rapidly filling up with competitors like Box, Sugarsync, Microsoft's SkyDrive, Google Drive, and Apple's iCloud. Dropbox's primary advantages right now is its 100 millon-strong user base as well as a head start when it comes to working across multiple platforms. The company is hoping that the new tools will press those advantages and help it in its quest to move beyond the increasingly commodified market of cloud storage and into a new space of providing content services instead of basic file sync, backup, and storage.

"It's less about the filesystem, going forward," Dropbox's Sean Lynch tells us, "and more about about the content that users are generating in these applications." Getting users to sync more app content into Dropbox is more important than just gaining a raw-number edge compared to other cloud storage providers. It actually means that Dropbox would have more opportunities to create value-added services that abstract those files into content-services like the photo album feature it released last week.

This new offering for iOS and Android developers will give a simplified set of tools for integrating Dropbox, whereas before developers had to manually create their own software to work with the company's more basic file sync APIs. The new tools should make life easier on developers as it abstracts the work of sync, offline caching, and background uploads.

The new Dropbox APIs are more of a direct attack on iCloud than its previous tools, which weren't as easy to implement as Apple's solution. iCloud is built into iOS 6 and is relatively easy for developers, but offers very limited and often confusing file access to end users — especially on non-iOS platforms.

Dropbox is ultimately aiming for a usable balance between traditional file system access on desktops, simplified and abstracted content on mobile, and above all cross-platform file syncing. It's much closer to hitting that target than its competitors may realize, but it's not likely that they will quietly cede the market to Dropbox. 100 million users may seem impressive, but Dropbox will need a lot more to stave off the likes of Microsoft, Apple, and Google.