Cycle Calculator for Women
Full user review
"can't accurately track your bleeding due to inability to edit"
If your cyle is always on schedule then it is fine to use (then what's the point?). However if you bleed more or less than the amount of days indicated on the program or your cycle doesn't fall on a certain 28 or 30 day etc. cyle (irregular), then it is not helpful to track your cyle or fertility.