tl;dr — Pivotal Tracker is the be-all and end-all of software development tracking. As a developer, I don't hold myself accountable to any work that isn't written down in a user story prioritized by my product manager — the only person to whom I answer. Requirements don't come from meetings; they come from this backlog. I take work off the top, and when it's delivered I can easily filter into a historical view of my…
For me, things aren't as rosy as it is for you. I do a lot of research-y learnings on the side and that isn't really tracked through any board.
750words.com looks cool though. I use vim to document my journal once in a while but should give this a try once.