Welcome aboard. As far as I know there is no care sheet for these frogs, but give me some time and I will write one.
I am a keeper and a big fan of Phrynomantis frogs. I currently keep two species, microps and bifasciatus. I do plan on breeding the bifasciatus some time in the near future and that will most likely be followed by an artcle. I need to get more microps before I can consider the same for that species.
As far as sexing is concerned, I believe I have two female and three male bifasciatus. This is based on the size of the animals. Based on the sizes of of the previous species, I beleive both of my microps are female. Of course I won't really be able to say for sure until I get them into a rain chamber and breed them.
All my rubber frogs (Phrynomantis sp) are fed fruit flies, bean weevils, and small crickets that are first dusted with vitamins and calcium. Shallow water bowls are proved as are artificial plants and/or hide boxes.
Now if I could just get my hands on Phyrnomantis annectens or affinis.....