Am not a registered member on howcan but i've checked it out and it's almost a complete duplicate from answeree with just a few differences on the points system.
Howcan is relatively new compared to answeree. I don't think there's upto 10 questions on the site for now. Every operation on the site is almost the same with answeree. The only difference is in the point system as said above. You get 10 points for answering, another 10 points if your answer gets chosen as best, and also 20 points if you answer a question first.
Another major difference on howcan from answeree is that every question is expected to start with How to or How can. There's no limits to number of answers given and 1000 points on howcan is equivalent to $1 unlike answeree. This is basically how much I know about howcan.