We've just heard from sources close to Sparrow that the man behind "Sparrow for Windows," Panos Tsimpoglou, was never hired by Sparrow CEO Dom Leca, and was never officially associated with the company's brand. "Sparrow for Windows" also did not use the company's famously speedy mail engine, and was merely a prototype, our source told us. The app was not even close to "weeks away" as Tsimpoglou had claimed, the source added.
Perhaps most importantly, Tsimpoglou wrote:
"I had asked specifically if the branding would be the same and that there would be no weird distinctions for the Windows app. We agreed that you were gonna go to sprw.me and if you had a Windows device you would get Sparrow for Windows"
He made it seem like Sparrow for Windows would take on a similar role as Instapaper for Android — an "official" app, but one built by another developer.
"We shook hands and we said we were gonna meet again in June/July for the final details"
Another source close to the situation informed us that this was "definitely not" going to happen, and it was never agreed upon that the app would bear Sparrow branding. What we're left with, sadly, is a simple Sparrow copycat for Windows that never came to be. The team was receptive to an enthusiastic developer that wanted to bring a Sparrow-like experience to Windows, but the parties never formally shook hands on anything.
To sum it up, Sparrow for Windows never existed.