Long time no see. This update was made possible by a donation! It was only meant to specify the api-version as 1.16, but I threw in a bunch of refactoring as well. Nothing new feature-wise, though.
Nothing is changed in the plugin, but I just wanted to let you know that I won't develop this plugin actively anymore. No need to worry, though, I uploaded the source code on GitHub and you can submit a pull request if you want something added:
https://github.com/Prunt/SimpleJail
Update version 1.1:
* Small bugfix
* Added command blacklist
NB! After this update, the "whitelist" section of the config will not be used and can be deleted. Plugin will generate a new "commands" section!