I currently have Pulse Audio Volume Control and I'm using it to control audio between my laptop & external monitor as well as volume of different apps.
Is there a faster way of controlling these (especially app volumes), from the music/sound taskbar for example?
I am open to experiment with other ways.
As of writing I have not found a solution for Ubuntu Unity. But having just moved to Ubuntu Gnome I was glad to find out several that are part of the Gnome desktop in the form of an extension:
Volume Mixer
(Media player indicator) for media players which supposedly has volume control but I haven't seen it yet. Maybe I need a reboot.
On a related topic the Gnome Shell Audio Output Switcher is handy to switch between audio outputs.
After trying the above I ended up with Volume Mixer and Gnome Shell Audio Output Switcher. Here's a screenshot: