Getting things Ready
You will need the below environments for developing your own plugin
A development environment for kintone customization
See here for more details
An environment to run the Packaging Tool
You will need to run the shell script that's introduced in the below Plugin SDK section.
If you're working on a Windows environment, use a tool such as cygwin to run the tool.
A Plugin SDK that contains the packaging tool, CSS file, README, and sample can be downloaded from the following link:
Check the below link for instructions on how to utilize the Plugin CSS file: