Ubuntu 14.04 Clipboard Manager?
I use ClipIt is a Parcelite fork with Ubuntu menu integration.
sudo apt-get install clipit
It works on both, GNOME 3 and Unity.
Glipper was a clipboard manager, it was removed from Ubuntu and Debian in 2018.
For *buntu 20.04 several options are available:
- qlipper
- clipit
- copyq
- diodon
- parcellite
You can try Keepboard. It is easy to use and seems to be stable and reliable.