Add a Graph option to each Form
When creating a new Form right after the Fields section create another section called Graphs.
And have them the ability to add multiple graphs from the following list which can grow in the future. Do it just like how you did Field Type List. Create Graph Type List.
1. Bar Graph
2. Line Graph
3. Pie Graph
Entering a Graph will require two number fields already created under the Field Section.
SO, in creating a Graph you need to Select the Graph Type, Select one of the number fields for X-Data and another number field for Y-Data and enter how data points to plot. So, if you enter 20 data points it will plot only the lastest 20 data points that was entered.
And if the Y does not match the X just error out or field it with zeroes for the missing data.
Tap Forms 1.5 has the ability to export and email records as a CSV file. The records could then be imported into Excel to perform graphing functions. That would be a workaround at the moment for this request. Well, when 1.5 is released that is.