Yahoo! has this morning announced that it has reached a deal to acquire popular blogging platform Tumblr for $1.1 billion. The company promises “not to screw it up,” and says that Tumblr will continue to operate as a separate business, with David Karp remaining CEO.

Just over a month after acquiring Summly for $30 million, Yahoo! has gobbled up another smartphone app. This time it’s Astrid, a pretty task management client for Android and iOS, which has a strong focus on sharing. Astrid announced the news on its blog today.