BitTorrent Inc's secure Dropbox alternative is proving a smash hit. The San Francisco company announced today that the Sync app now has one million users, who together have transferred a total of 30 petabytes. In addition to the impressive statistics BitTorrent announced several improvements to the Sync application, as well as an API which allows third-party developers to create new tools based on the platform.

BitTorrent Sync is a relatively new tool that allows users to securely sync folders across multiple devices using the BitTorrent protocol.

In terms of functionality it’s comparable to most cloud-based sync tools, except for the fact that there’s no cloud involved. Users simply share their files across their own devices, or the devices of people they invite to their private folders.

Combine the above with no limit on file-sizes or bandwidth and a smash hit is born.

The free application was first released to the public in January and today BitTorrent inc. announced that it has already passed the one million user mark. The company further informs TorrentFreak that together these users have synced over 30 petabytes of data thus far, up from eight petabytes back in July.

The success has motivated the San Francisco company to put a dedicated team of developers on the software, which has resulted in several updates and improvements in recent months.

Today BitTorrent Sync 1.2 was released and one of the key changes is a doubling of the maximum transfer speed. Sync was already quite fast as files are not stored in the cloud, but the latest release bumps the transfer speeds to 90 MB/s.

“Sync skips the cloud to deliver files faster than server-based alternatives, like Dropbox. And with 1.2, we’ve boosted Sync’s speed performance. The app’s been clocked at 90 MB/s on the LAN. Which means your 10 GB file will be synced in less than two minutes,” the BitTorrent Sync team notes.

The new release also offers several updates and improvements for iOS users, including an iPad app to sync photos.

“We’ve updated Sync to include an updated design, improved connection speed, iOS7 compatibility, and a native iPad app. We’ve also added to the iOS feature set. You can now send and sync files in other apps using Sync, and save media from your Sync folders direct to your camera roll.”

Finally, BitTorrent has released an API. The company hopes this will encourage developers to create a wide variety of Sync based apps, such as social networking or secure chat tools.

“The new API will allow developers to create distributed social media, communications, and enterprise apps on top of the platform. It’s designed to work across major operating systems; including Windows, Mac, and Linux.”

With the latest improvements and the new tools BitTorrent hopes to reach an even wider audience, especially among those who want full control over their own data

“Our goal is to build a sharing tool that lets you move big files, and big ideas, freely. Without surveillance. Without speed limits. And without size caps. Your data belongs to you. Sync is designed to keep your stuff yours; with you and your team, wherever you are,” the Sync team notes.

The latest version of BitTorrent Sync is now available for download here, completely free of charge.