https://github.com/danielgindi/ios-charts/blob/master/README.md
http://www.appcoda.com/ios-charts-api-tutorial/ I'm going to add some graphing to the app soon.
Haven't tried this yet but it looks good.
DynamicGraphView Core Plot
http://www.raywenderlich.com/13269/how-to-draw-graphs-with-core-plot-part-1
http://www.raywenderlich.com/13271/how-to-draw-graphs-with-core-plot-part-2
I had a couple of difficulties using it in a newer version of Xcode so added my findings here. iOS Plot
https://github.com/honcheng/iOSPlot iOS Charts
