What do you use to outline / plan?

So what tools are people using to develop their games?

By tools I mean editors, software , apps…etc. I’m new to this but I’m thinking these games are a perfect fit for flowcharts . Any good software you can recommend ? I know visio…but does it scale well with so many paths in a game ? Thanks !

Thanks…the forums have so many topics…hard to search them all. ! Thanks again !