So, similar to the Gnome dropdown terminal plugin? I've never really seen the use of these types of tools. Your terminal should be fast enough to spin up a new window instantly, so opening it on its own is hardly an inconvenience. The bigger problem tends to be in how they obfuscate the program running behind it, which has given me some grief in the past with regards to updating configs.

If people find it useful, though, more power to them.