Zoom, for one (3)
I believe the answer is:
app
'zoom for one' is the definition.
(I know that Zoom is a video-conferencing software)
This is the entire clue.
(Other definitions for app that I've seen before include "Software for mobile devices, in short" , "Program for a smart phone, in short" , "Software item" , "Software program for a mobile device" , "bit of software" .)