Twitter has acquired Cover, an Android lock-screen replacement that automatically places apps that it thinks you'll want to use front and center based on your location and the time of day. Cover suggests that development will cease on its eponymous app for the time being, though it says that the app will remain available in the Play Store. It's likely then that Twitter isn't interested in taking over your lock screen so much as it's interested in Cover's creators and their experience with intelligently surfacing information — something that it can certainly put to use.
The acquisition appears to be about talent
It's also possible that Twitter is looking to flesh out its Android team, which recently saw the loss of Sara Haider, one of its key Android app developers. That said, sources tell us that this acquisition is unrelated to the Haider's departure. Haider was most recently working on Vine's Android app, while the team from Cover will be working at Twitter directly.
If Twitter is interested in taking over your lock screen, this acquisition would instead be the start of a far more ambitious initiative. Facebook attempted something similar last year with the launch of Facebook Home, and though it's failed to gain much traction in the time since, it's clear why Facebook gave it a shot: taking over a phone's lock screen would give it a powerful advantage by making its own content the first thing that a person sees when checking their phone.
Twitter could also try for something like this by expanding Cover's abilities beyond apps and into tweets, news, and trends. For now though, it appears that Twitter isn't interested in controlling your lock screen — it's certainly seen the lack of demand for Facebook Home, after all — but we may just see a smarter version of its Android app sometime down the road thanks to the Cover team's background in using contextual information to change what an app chooses to show you.