Most likely, if you let it run in the background anyway... You can set how often it should pull information from the feeds you have set... I have mine set to every 2 hours but I usually close the app once I'm done reading the stuff and just let it fetch new news when I wanna see what's going on in the world...
Viigo is awesome though! It's like my daily newspaper... lol
YEAH Viigo is cool. I do they same as StevenG I don't let it auto update. So every time I open the app it will search for new content and then I read it, delete it or what ever and then close the app. I really haven't had major problems with memory leaks because of Viigo or battery issues.