If you're looking for Jace Norman on Snapchat, you'll be disappointed to know that searching and adding all the "Jace Norman" related profiles won't help... A friend of mine added everyone she could find on Snapchat with Jace Norman and Harry Danger related names, and none of them were genuine. Not even one!
The truth is, there is no way of knowing what Jace Norman's Snapchat name is. He probably uses a completely different username, and he probably wants to keep it private.
At this point, we don't even know for sure that he's still active on Snapchat - I dunno about you, but it seems like a lot of my friends have moved away from Snapchat and on to Kik and other apps.