If you need to share plans across a whole company on an online platform, there are quite a few tools for that. However, if you want to keep track of your todo list, version control your project plan, make an ideaboard, and plan your project your way, MasterPlan is the tool for you.
Note that this is the code repo and internal-ish issue tracker for MasterPlan. Releases can be purchased from itch or Steam. You can build it yourself from this repository if you're familiar with Go.
A few days before the initial commit to this repository, I was working on an indie game, and thought I needed a tool to help me plan out the rest of it. I asked on Twitter for some suggestions of software to try, and found that while they were solid choices, they weren't as applicable to independent development as I would have liked. Most project management software is designed for use by a large team, or even a large company. The disadvantages of many project management tools available today can be due to the features they offer, as they may not be applicable to small teams:
While these features (cloud-based, browser apps, etc.) can be beneficial for large groups of developers, they can also become sticking points for individuals or small teams. So, I decided to make a tool myself to help independent developers plan out projects such as these. And so, the result is a simple, compiled, downloadable application that stores project data on your computer. The project plan file are plain JSON text files, and can be easily committed to a version control system. The goal for MasterPlan is to make a project management and visual planning tool that is easy to use and extremely simple. I believe it is reaching this goal.