Online notes platform Evernote has been growing rapidly over the past year and is putting some of its venture funding to good use: A developer app-building contest with $100,000 worth of prizes.

Evernote has raised around $45 million with its latest round a Series C $20 million injection in October 2010 from Sequoia Capital. Developers can use the Evernote API to build extensions or features onto the platform with the grand prize winner taking home $50,000. Evernote developers and users: what do you want to see built onto the platform?

Curious what to create that Evernote has not already built itself? See what they have to say on their contest page:

"When coming up with your app, be creative," the company wrote. "We're not expecting an Evernote-powered jetpack (though that would be sweet) but, why not create an Evernote-enabled location-based shopping companion or a game that uses your notes to strengthen your memory? The possibilities are endless."

Busy Growing A Platform

Evernote was founded in 2007 and has around four million users across any operating system or device you can think of. It can clip the web, save personal notes, record audio from a mobile device and upload to the web, store pictures or articles to read later.

It has been busy rolling out updates over in the last couple years. Its Windows app got a social feature, redesigned its iPhone app, made its Android app more secure, updated its Web interface, integrated with StudyBlue, opened an app store, created a Mac interface, will introduce Android tablet functionality, created a Web clipping extension for Chrome and other browsers and created sponsored accounts.

So, it has certainly been putting its funding to good use. Perhaps they are out of ideas after rolling out so many new features, mostly in the last six months. Nothing better to dangle a carrot to developers and have them create new features for your platform. The move is similar to what Netflix started in 2009 with a developer prize of $1 million to create new products, features or technology to its predictive technology.

We wrote in Jan. 2010 that prizes can be a good way to foster a community around your platform, support innovation, gain recognition and create a set of challenges for developers to strive for. Contests are also a sign that a company has matured past just trying to survive the market and trying to conquer it, a la Netflix and its competition.

Another sign of Evernote's maturity is their first conference - the Evernote Trunk Conference in August in San Francisco. Winning apps will be showcased then.