Of course, there are some major caveats here, which is that, firstly, in order to use this web-app you first need to be fairly proficient at Sutton Signwriting, i.e. you might need to try around for a bit between different similar handshapes before you find the exact right handshape that a sign is listed under; secondly, there seems to be no way to exclude certain features from your search, which means that you might have a lot of irrelevant results for a given search; and thirdly, the dictionaries naturally don't contain every single sign in every single sign language, and this is probably extra pronounced for smaller sign languages. A particular thing to note with regard to the dictionaries is that since this web-app is from 2017, you won't be able to find signs like CORONAVIRUS or RIZZ using it. The glosses provided for the signs also naturally don't provide all the shades of nuance, for instance you'll find both two-handed and one-handed variants of letters in SignMaker's Norwegian Sign Language dictionary but no indication of which version is more common.

Nevertheless, even with all its faults, I still find this web-app useful from time to time. I don't think there's any other program or web-app in the world that lets one search SL signs by their parameters, despite how useful such a feature could be for learning signs. Every other sign language dictionary in existence it seems is basically just a list of glosses in alphabetical order, each gloss accompanied by a video or diagram. This means that other dictionaries can fairly conveniently answer the question "What is the sign for [word]?" but not "What does this sign mean?"

So for instance, say I saw the Norwegian Sign Language sign for bull or ox (NO: okse), but I didn't know that that's what that sign meant. In order to identify the sign, I'd go into the Norwegian Sign Language version of SignMaker; I'd click on "click search" and select "2 clicks"; then I'd find the icon for "index thumb" (note: hover your mouse over the icons to read descriptions of them), and click on that; then I'd finally find the icon for "Index Thumb Side, Thumb Diagonal", and click on that. The green window on the left-hand side of the screen would then display a series of results for Norwegian Sign Language signs containing the selected handshape, in this case six results including two variants of the sign for bull. So then I just hover my mouse over the relevant result, and the gloss should appear.

So that's how you use it, basically, and I think that's a pretty neat thing to be able to do.