Sparrow for OS X has just received what could very well be its final feature update. When the popular mail client was acquired by Google last month, its developers made clear they had no plans to add new capabilities to the app. Assuming that's true, it means version 1.6.3 has been in the pipeline for some time — perhaps before any deal with Google was finalized.

If you were hoping to see Sparrow go out with a bang, however, you may be somewhat underwhelmed with the list of tweaks and minor additions found here. According to update notes, the app's performance when dealing with "huge" email conversation threads has been improved. Further, URLs in the subject line are now clickable and users are finally able to select information in the date / subject fields. IMAP support is also said to be better, which we imagine is welcome news to those planning to stick with Sparrow despite its essentially defunct status.

A number of bug fixes and Brazilian localization round out the latest release, available now in the Mac App Store. Savor the moment, because barring the critical bug fixes Dom Leca and his team have pledged to deliver if necessary, this might be the last time you hit that update button.

Update: As pointed out by ryangoins in comments below, this update was made available to non-MAS customers some time ago, but has just now made it to Apple's digital storefront.