Graphs used in Sleep Cycle iPhone App

Does anybody know what graph framework/api/etc. the developers of the Sleep Cycle app (http://mdlabs.se/sleepcycle/) used in their application?

Thank you in a开发者_开发百科dvance!

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http://code.google.com/p/core-plot/ I would say,unless it's custom implementation. BTW, rolling your own custom graphs is pretty simple.