Recognition of the hand of his gesture

Hello everyone, I wanted to know if anyone can give me some advice on how I can do so on unity, without using vuforia to recognize the hand, in particular.

To recognize two particular gesture:

1) recognize the open, frontal hand

2) recognize the back of the hand, with the closed fist

I would like to make sure that if I find myself in situation 1 I show a certain object on the hand, if I find myself in situation 2 I show another one. If I do not find myself in either one, I do not show anything.

What I want to do and use, the Markerless Augmented Reality on the hand. Although I do not know if in this case we can really talk about Markerless.

I am reminded to use OpenCv, but since there is only one package and it is paid I would like to avoid. You could do it without OpenCv according to you, if you like?

P.Š. is an app that must run on android.