decided to make my own : D and recycle this fruit crate that remained from some oranges.
This is how I did it.
Basically I just took one side of a the fruit crate and just reinforced it with the other piece of plywood, from the other side of the crate.
The triangular support wood from the corner, I've cut it to an 45' angle or you can try whatever suits you...
Pierced two openings for the tablet to enter, for portrait on one side & landscape on the other side.
(the measurements you should do on your own, this depends on the type of the tablet or the case you own).
and in the end aesthetically fill holes with some wood putty and paint it however you would like it.