The app, which was launched six months ago, learns the frequently-used apps for a user and the time of day for their use and puts them on the lock screen for ease of access. The announcement was confirmed by Cover in a blog post; details of the deal aren't available as yet.
"Twitter, like Cover, believes in the incredible potential of Android," the Cover team said. "They share our vision that smartphones can be a lot smarter -- more useful and more contextual -- and together we're going to make that happen. We'll be building upon a lot of what makes Cover great, and we're thrilled to create something even better at Twitter."
It is still unclear why Twitter acquired Cover -- for its talent or to incorporate the app's features into Twitter for Android. But they aren't the first company to acknowledge the importance of the lock screen. Last week at Microsoft's Build conference, the company showed off customizable lock screens on the Windows Phone 8.1 operating system.