Git GUI client (by Atlassian)
Sourcetree is Atlassian's free Git GUI client, notable because it's made by the same company behind Jira.
Being an Atlassian product, Sourcetree has reasonably smooth Bitbucket integration if your team happens to use Bitbucket instead of GitHub or GitLab.
Despite being made by Atlassian, Sourcetree doesn't automate Jira ticket transitions either — it's a visual layer over git commands, not a Jira workflow tool. You'd still need something like Jitly running alongside it for the ticket-sync part.
This is really the whole reason Jitly exists — it's not trying to replace Sourcetree at what Sourcetree 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 teams on Bitbucket who want a free visual git client from the same vendor as their Jira instance. If that's not you, this comparison probably isn't that relevant to your day — Sourcetree and Jitly solve different problems most of the time.