A developer who worked with the Sparrow team has divulged his work on a Windows version of the popular email client, and says that a beta was due sometime in the next few weeks — that is, until Sparrow was acquired by Google and ceased its development efforts earlier this week. The developer, Panos Tsimpoglou, details the effort in a blog post, and says that he had been "green lighted" by Sparrow CEO Dom Leca after pitching the idea over email about a year ago. After he got the go ahead, Tsimpoglou says that he traveled to France in April to meet with Sparrow's founders to discuss the project, and that the group agreed to meet again in June or July to work out the final details — a meeting that never happened.

While Gmail users may be looking forward to the results of Google's talent grab, some of Sparrow's existing users aren't too happy about owning a mail client without a future — with today's news, we know that both iPad and Windows users were set to receive versions of the app. Like Sparrow's fans, Tsimpoglou is also disappointed. He says that he first found out about its acquisition when news hit the web, and that after emailing Dom about the situation, he received a terse response:

Hey Panos,

Thanks for your kind words.

The press release is right. Sparrow development is put to an halt.

Dom Leca

Sent with Sparrow

Tsimpoglou says that his thoughts are mixed, but that "mainly it's sadness for what could have been and truly is a great app for Windows." You can check out several videos of the Windows client along with Tsimpoglou's full story at his blog.

Update: Sources have informed us that "Sparrow for Windows" was never an official Sparrow client, that the project was not close to being "weeks away," and that Tsimpoglou was never hired by Sparrow CEO Dom Leca.