Twitter on Monday said it now has more than 1 million registered applications on its network.

[ad#Google Adsense 300×250 in story]According to Twitter, those apps have been built by 750,000 developers. The surge to 1 million apps came quite quickly — just one year ago Twitter only had 150,000 apps.

That equates to a new app being registered every 1.5 seconds, according to Twitter.

“Since December 2010, more than $500 million has been invested in ecosystem companies, and more than a billion dollars has been paid out in acquisitions,” wrote Twitter. “This level of investment is indicative of the opportunity for developers and entrepreneurs to build successful businesses as part of the Twitter platform.”

In announcing the news, Twitter also unveiled a new developer site “where anyone in the ecosystem can start building with Twitter, connect directly with Twitter team members, exchange ideas with fellow developers, and find all the resources they need to create their own product or business.”