I've looked for mechanics to assist with solo role playing without dice and other material objects. It seems a little weird at first, but once you start using it, it is easy to remember. This fit the bill. I've used a mashup of Diedream and Push while idle or doing tasks that don't require a lot of thought, such as yard work. Though there ends up being a lot of math. Simple math. Still if you aren't good at doing it in your head, you're tired, or lacking mental energy, it can slow the flow of play.

Overall though, I've found this a a helpful inspiration for solo gaming. Thank you for sharing it.