Periscope is a live streaming app for both iOs & Android mobile devices. Originally a start-up, Periscope was purchased by Twitter in March of 2015. After the purchase by Twitter, Periscope became readily available to anyone with a Twitter account. According to Tech Crunch, Periscope saw over a million sign-ins during it’s first 10 days. Periscope continues to grow in the live stream scene, leaving the competition in the dust. As of posting, Periscope now has over 10 million users.