The simplest thing that might work is a pen and a notebook. And a jpg with an iPhone to digitize the sketch. Documentation is a practice not a tool. A shitty

The simplest thing that might work is a pen and a notebook. And a jpg with an iPhone to digitize the sketch. Documentation is a practice not a tool. A shitty process can be improved. Without process "the perfect tool" just sits collecting dust. Or a person wants to start documenting, so they shop for documentation tools. Now they have two problems. Good luck.