Legacy agile tracker
Pivotal Tracker is one of the original agile-focused trackers, still used by some older codebases though it's seen less active development in recent years.
Pivotal Tracker's point-based estimation and automatic velocity tracking were ahead of their time and some teams still prefer its simplicity over Jira's endless configuration options.
Its git integration story hasn't evolved much — commit message conventions still do the heavy lifting, same manual approach this whole comparison series has been talking about avoiding.
This is really the whole reason Jitly exists — it's not trying to replace Pivotal Tracker at what Pivotal Tracker is good at. Jitly's job is narrower and more specific: jitly start ABC-123 creates your branch and moves the Jira ticket to In Progress in one shot, jitly done commits, pushes, and updates the status to whatever your team's workflow has, fetched live so it never gets out of sync with how your Jira is actually configured.
Mainly existing teams already using it on long-running projects, less commonly a first choice for new teams today. If that's not you, this comparison probably isn't that relevant to your day — Pivotal Tracker and Jitly solve different problems most of the time.