Hi there, and welcome to the forums!
I had an LG G3 for a little over the year, and used Snapchat for that entire year; with very minimal problems. I never had problems with updates, and the only time the app lagged or stuttered was from my own doing (i.e., I closed the app by accident while uploading a snap to My Story, etc.).
As far as picture quality goes with regards to Snapchat and Instagram, I'd say the LG G3 does a pretty good job; especially for its iteration in the LG G lineup. Obviously phones like the LG G5 will be better camera-wise because their specs are better, but the G3 takes decent shots and I really liked the camera settings (i.e., there was one that would really focus on the details of the shot - I think it was called "Magic Focus" - and I really liked using it). I really recommend tinkering around with the camera settings to see what you like most. Good luck!
01-24-2017 06:36 PM