Betabeat has written before about Medialets, a fast growing New York start-up that's beating Apple on its home turf, capturing the lions share of blue chip publishers on platforms like the iPad.

Today Medialets introduced Muse, a self-service platform that lets publishers plug their "creative" into a set of templates and easily layer features like mapping, social widgets and photo galleries on top.

Considering how quickly the app ecosystem is growing, this seems like a big opportunity. A lot of smaller developers are going to be interested in using rich media ads when they develop for smartphones and tablets, but won't have the budget for a $500,000 iAd campaign.

Medialets claims that users can create an ad in as little as 15 minutes, which raises the possibility of folks firing off some half-cocked ads. Luckily there is also a collaborative workspace where users can spend a little time thinking about their message before firing off a Groupon Superbowl style mistake.