Assist recording weights and display it graphically to know the change in fat mass.

FEATURES:
-record weights(kg) and body fat percentage.
-tweet the change in fat mass comparing to apples.(optional)
-draw a line graph.
-draw a graph to display the daily / weekly change.
-import a CSV(TSV) file.
-export a data file via email.
-update: record blood pressure and heart rate.
-update: check the input data in the table.