This is the demo version of the full version, you can save 30 days on this version. Feel free to email me with any feedback/bugs/questions/feature requests. Charting app can be used with Billings method, designed with the Creighton model in mind. Compare 2 cycles and/or date range of days next to each other, including the temperature graphs.
The antivirus report has confirmed that Charting App Demo is completely safe for usage. John Schmalenberg is the developer of the tool which is listed among the Medical tools category. The most recent update was on Jun 27, 2015 and this application was downloaded and installed by over 10K users.