There is also a UI extension version available of it here: http://appstore.sdl.com/app/publish-from-publishing-queue-extension/632/, but I have to first tell you that we are currently still busy with the migration of all extensions from SDL Tridion World to the new SDL Appstore (nice that you found it already there ;o).
The installation instructions of the UI extension (which was last updated for 2013, so for Web 8 you will need to make some modifications by the way) are uploaded on the appstore, but they are not visible yet (a technical issue that is being worked on). So if you want to use the UI extension, then follow the installation instructions here http://www.sdltridionworld.com/community/2011_extensions/publishfrompublishingqueue.aspx and for making the required changes, you can get the complete source code of it here: https://github.com/bkoopman/sdl-tridion-world/tree/master/Publish%20from%20Publishing%20Queue/trunk
As mentioned the appstore is not completely live yet (I'll notify the team about the download issue), but more importantly, the extension was last updated for 2013, and never properly tested on Web 8.
I just did a quick push of a few changes to https://github.com/bkoopman/sdl-tridion-world/tree/master/Publish%20from%20Publishing%20Queue/trunk which might be working better for Web 8 (not trying to reuse the icons from the CME but adding its own). I didn't test it, so if you find more issues, let me know and we can maybe look at solving it together.