The free online version of Jonas Method Calculator (but renamed into Lunar Conception Calculator) is again available on Lunarium. Everyone can calculate their phase return moments and, if the information is going to be used for an attempt of conception, there is an indication of gender of the child that can be conceived then.
There is also an article explaining the idea of the method and describing the research which was done around it: Lunar Conception: a Discovery of Dr Jonas.
All this should be sufficient for healthy individuals without a heavy karma who want to conceive a child of a desired gender, or for those who want to use their phase return for achievements in sport.
As for those who are having a problem with conceiving a child, there is a special service offered by Odan Institute. There, you will have an experienced astrologer working individuall…