I need to develop an application on both iphone and android which have to support chart plots.
(Or perhaps a similar chart library for ios/android platforms.)
Or what do you recommend?
If your app will work only online you can use this:
I've seen plenty of flot tutorials for Android, and according to this link flot works fine on iphone except for the mouseover events.
I recommend looking into building the application using Adobe AIR.
Please try this one for iOS: https://github.com/danielgindi/ios-charts
It is inspired by an Android library called MPAndroidChart.