[chch]

I've been using Shape Catcher for a while for my non-CJK needs, but the best tool I've found that for Unihan characters has been the one from LINE[1]. Specifically, unlike others I've used, it tends to do a good job with semi-cursive/calligraphic writing. That makes it faster to look up complicated characters (because you can scribble a bit), plus it's useful when you don't actually know exactly what the "original" form of a character is, and have to just draw it from sight.

e.g. if you see [2], and don't recognize it, but can draw it into the tool, you can get 而 correctly, without having to draw the very specific stroke order[3], like in other tools.

It's made for Chinese, but I often use it for Japanese, too. :)

[1] http://ce.linedict.com/dict.html#/cnen/home

[2] http://www.ryuurui.com/uploads/1/5/4/8/15489306/6738815.jpg?...

[3] https://upload.wikimedia.org/wikipedia/commons/2/2a/%E8%80%8...