Milanote is a tool for organizing projects into kanban like boards. It’s targeted at creatives, and comes with a variety of templates, not only for writers but for fields as diverse as game design, interior design photography and software development.
You can write notes and todo lists, upload images & files and save things you find on the web, which is pretty typical for this sort of software. Where Milanote differs from other products mentioned on this site is the way you can organize things visually.
Crucially, you can export your boards as pdfs or pngs, or export them in doc, md or txt format.
There is a free version available with no time limit. The PRO version is $9.99 per month (monthly and annual plans)
Disclosure: Milanote shared a lifetime subscription with me in return for writing this post. I must admit, I’m a plain text sort of guy and always will be, but if you think in pictures and not in words, this may well be the tool for you.