Name: Nautilus Terminal
Open source: Yes, GPL-3.0
Why: It adds a terminal to Nautilus window (like in Dolphin), and I can't live without it. It increases my productivity massively. We have all of its dependencies in the repos already, and packaging is really easy. It didn't cause any problems with previous stack updates.
You obviously can install it with pip, but accepting it would be more convenient and make it discoverable for more users.