I have thought about it and would like to see an app on my phone for devinity. This app could include: How many people are on each server, a possible spectate mode like on BF4 ( this would probably lag the server a lot but it is just an idea), also maybe some important updates, and maybe some highlights of the game today. I know that this is a farfetched idea, but thank you for your considoration and your time.
The forums page is already mobile-friendly. You can view the players on each server on the Garry's mod flood 1.7 page. You need to rotate to landscape though. Spectate on mobile is not worth it...
Too much work for such little gain in my opinion. I really doubt that many people would even use the app when, as Pit said, you can get all of that info on the forums.