Email client Sparrow has been acquired by Google for an unknown fee in a deal that will see the search giant work with Sparrow to "accomplish a bigger vision."
UPDATE The Verge claims to have spoken to a source "familiar with the situation" who has said that Sparrow was sold for less then $25m (£16m).
The website said: "The talks have been ongoing for a while; Sparrow was well known, and our source said Google recognized that the five-person-team had a 'lot of expertise in how to make mail communication really simple'."
Writing on the email client's homepage on 20 July, CEO Dom Leca said: "We're excited to announce that Sparrow has been acquired by Google! We care a lot about how people communicate, and we did our best to provide you with the most intuitive and pleasurable mailing experience.
"Now we're joining the Gmail team to accomplish a bigger vision - one that we think we can better achieve with Google."
Available for Mac OS X and iOS, Sparrow went on sale in the Mac App Store on 9 February, 2011 and became the top paid and top grossing app in its first day.
An iOS version for iPhone, iPad and iPod touch was released to the App Store in march 2012 and is one of very few email clients allowed by Apple to be used in iOS.
Despite being taken over by Google, Sparrow will remain available for users to download and use, although it's not yet known what plans the two companies have for future products.
Leca added: "We'd like to extend a special thanks to all of our users who have supported us, advised us, given us priceless feedback and allowed us to build a better mail application.
"While we'll be working on new things at Google, we will continue to make Sparrow available and provide support for our users."
Sparrow added to its Mac App Store product description: "As the team works on new projects, there will be no new features released for the Sparrow apps, other than minor maintenance and bug fixes."
Where before Google offered Gmail for iOS, but no stand-alone application for Mac, the company now has ownership of arguably the best application for on both platforms, and presumably with designs on creating an Android version too.
Leca signed off saying: "We had an amazing ride and can't thank you enough.
"Full speed ahead!"
Google has yet to make an announcement, although it will probably do so on its blog soon.