Couple advices probably won't fix market problem at hand but reduces lagging on market and in game and less crashes(this happens because of ram or processor shortage)
Even if u stop app's from running in background with some programs like "clean pal" they still come back but with this method they oftenly won't.
1- Go to settings>application manager on your android and delete everything(i mean everything don't miss one on the list don't worry phone will be alright) except simcity. it will ask go to factory settings with some of them click ok then make all "disable" and "force to stop"( if u delete google play, game will want upgrade for it. do it or not it's your choice but i recommend deleting that too.)
2- Disable all app's notifications including simcity
3- Go to "google play" settings and unrelate every game from google play account except simcity, close everything "google play" does in background from settings like "location" etc.
After those game doesn't lag and crashes sometimes but way lesser than before. I use s4 mini.
