Lets you scroll with two fingers on your trackpad within Google Maps
Chrome web store link: https://chrome.google.com/webstore/detail/scrollmaps/jifommjndpnefcfplgnbhabocomgdjjg
After checking out the source, initialize the dependencies using npm init.
After making changes, build a development version using grunt dev. This will create an unpacked extension under gen/plugin-10000 that can then be loaded into Chrome as an unpacked extension.
You can also use grunt watch to watch for changes and build new dev versions automatically.