This app was mentioned in 4 comments, with an average of 1.50 upvotes
For Android? I use NZBManager.
It supports SabNZBd, NZBGet, Sonarr, Sickbeard, CouchPotato, Headphones, transmission, deluge and uTorrent.
It's pretty fantastic, though it does have load issues every once in a while (with Sonarr, at least).
I love being able to check on my HTPC services all from one app. From what I can tell, it supports SABnzbd, NZBGet, Sickbeard, Sonarr, Couchpotato, Headphones, Transmission, Deluge, and uTorrent.
Reminds of this that I've been using for awhile now: https://play.google.com/store/apps/details?id=nl.timkatgert.nzbmanager&hl=en
NZBManager works great!
https://play.google.com/store/apps/details?id=nl.timkatgert.nzbmanager