I’ve been using Notion to integrate the kanban board, free form notes & references, client proposal documents, etc. all into one place.
I use Restyaboard to integrate the kanban board, probably the best looking and working kanban out there.
Readit Newsproductmaster21 commented on Ask HN: Solo devs, how do you plan your development? · Posted by u/going_to_800
There's a free to use hosted service or host your own via a 10min install including https setup (runs fine on a $3 2GB Ubuntu VPS)
https://jitsi.org/