HabitLab is a Chrome extension to help you build better habits online. HabitLab aims to help people achieve their goals online (ie, waste less time on Facebook) by trying out different interventions in their browsers and seeing what works best.
Install HabitLab on the Chrome Web Store
Translate HabitLab on Transifex
You can write new interventions within HabitLab without any setup or sideloading: Write New Interventions for HabitLab
Otherwise, if you want to build and sideload the HabitLab chrome extension yourself: Developer Guide
See the Wiki for more documentation