This app calculates the venus sign of your lover by filling in his birth date. The venus sign then tells you what kind of lover he is attracted to. This is because the venus sign represents what people find pleasing or appealing. This attraction is based more on love than lust, though it can mix up together for some men. This is because the venus sign is the planet of love and beauty, so it is what a man finds appealing in a woman.
When you know the venus sign of your lover you know what he likes in a woman. You can find out if you astrologically have some similarities to that sign or you can choose to amplify certain traits that are written about for that particular venus sign if you already have them. It is not meant to totally change your personality into the venus sign your guy is attracted to, otherwise it is kind of a mask that is not based on real mutual attraction, so you might be aware of this when reading the traits he is attracted to according to his venus sign.