Twitter is testing out a Periscope button for select mobile users

Twitter has started testing out a new Periscope button on some mobile users, allowing you to easily start a live Periscope broadcast and tweet it out right from the Twitter app. SEE ALSO: Here's how Twitter @mentions are changing The new live button appears next to the photo and video buttons when you compose a tweet, which you could easily miss if you pull up your keyboard immediately.  Image: pete pachal/mashable The test has only rolled out to a small group of iOS users, a Twitter spokes