CEO Dick Costolo shared some interesting stats about Twitter’s growth, including that it has more than 100 million active users and that signups via iOS device have tripled since the launch of iOS 5.

Twitter has been on a roll in recent months. The companysurpassed 200 million tweets per day in June but has since jumped to nearly 250 million daily tweets. The growth has been tremendous: Twitter had around 100 million tweets per day in January 2011.

Costolo shared these stats during an interview at the Web 2.0 Summit in San Francisco.

Of those 100 million global active users, half of them log in daily. “We had 30% of our monthly active users login in every day at the beginning of the year. Now it’s over 50%,” Costolo revealed.MORE