Twitter on Monday announced that the number of applications registered at the popular microblogging service has topped a million. Word of the milestone came as the San Francisco-based startup launched a new website at dev.twitter.com for software developers interested in tailoring fun, hip or functional programs for Twitter. \"Application developers play a fundamental role in helping people get the best out of Twitter,\" the firm said in a blog post. \"Apps help people understand and make the most of Twitter.\" Third-party applications tailored for Twitter range from games and picture posting programs to software tools for mining trends or other information from the flood of terse text messages fired off around the world each day. A new Twitter application is registered every 1.5 seconds, with the number of \"apps\" soaring from 150,000 a year ago, according to the startup. Founded in 2006, more than 200 million people are reported to use the service for sharing news, thoughts, pictures and more in text messages of 140 or fewer characters. A recent study by the Pew Research Center said 13 percent of online US adults use Twitter, up from eight percent in November 2010.