Top
Goes to the last submitted commit. That's the tip of the repository's main history, which is where you usually want to start a new stack of commits.
tw top
Output:
switched to commit #5v1 c/12v1
If you're already there, you'll see you're already at the top.
top loads the commit into the working directory, like goto. Twigg finds the commit by walking down from your current commit to the nearest submitted one, then up through submitted children until there are none left.
Dirty working directory
top refuses to run if you have uncommitted changes. Pass --force (short form: -f) to discard them:
tw top --force
top is also an alias you can pass to other commands, for example tw rebase top.