Good libraries to solve difficulty questions

resource.md

Markdown Cheatsheet

link: https://github.com/adam-p/markdown-here/wiki/Markdown-Cheatsheet

Ruby Geocoder

link: http://www.rubygeocoder.com/

npm

location of node_modules when use gobal -g

/usr/local/share/npm

Cordova

Simulator error FBSSystemServiceDomain code 4

Go to the iOS Simulator menu and select Reset Content and Settings.
Alternatively, you could quit and reopen the Simulator