you can farm coins if you have an android, simply use an app called Parallel Space. On it you can make a copy of quidd that doesn't take space and create a new account, there you can make as many as you want and harvest your quidd coins.
Link: https://play.google.com/store/apps/details?id=com.lbe.parallel.intl
I'm not sure if it exists for iPhone though you can try to look for it or a similar app that at least let's you trick the app into thinking it's on another device while at the same time keeping the original, letting you get double or triple the amount of coins you could normally get