The name of this program is Gender Recognizer, but it says it attempts to recognize male/female faces. Quick lesson:

Gender: boy, girl, etc. (some cultures have more than two of these[0], and others do not identify with either of those two)

Sex: male and female

In other words, if your goal is to try to determine if someone is XX or XY, "gender" is not the word to use.

Regardless, I would tread lightly with this, because this could presumably be used on pictures of transsexuals and transgender people. Also, incorrect matches for something like this would be very not cool.

[0] https://en.wikipedia.org/wiki/Gender_in_Bugis_society

Oh! I did not considered this part at all, I simply concentrated on the program. Thanks very much for your advice.

I have learned one very basic aspect about software project. That was really wonderful. Thank you. :)