The Crusher Matrix Board is just what I need at the moment, and I will recommend it . Some people will say that a board is a board but thats very silly. The fingers are the primary link in climbing, if you have strong fingers at least you can hang on. Thats why climbing finger boards are often called Hang Boards. However you should ideally be able to pull as well as hang, so you need a bit of width to un traumatize the shoulders. Crushers Matrix board is 700 cm wide, which is a comfy width for pull ups.
There's a stack of well designed holds, all in super gentle on your skin wood. The guy who makes them is a climber who understands fingers and has spent alotta time on this board. there are different combos to use, theres a slot which allows pinches, theres a ton.
Big jug in the central region for big one arms. Big slopers for comfy pulls at the side.
There are some difficult holds. The monos are what I got the board for, they are preety much first joint and every one but experts will need a foot stool to take weight off on the two sets of small holds.
Mr Crusher has got a wealth of information on his web site, which includes advice on how to use this board, you should check it out. There are other boards too, but this one is in my opinion the most comprehensive. It is also very reasonable in price, I dare say it is the best bang for your buck in finger boards.
Another thing is its very light, I am taking one on a trip next week, because fingers first, eh?