Create, Pull, and Push Branches
Dragging a branch in Tower's sidebar leaves you with many options:
Drop it onto the section to create a new branch based on the dragged one.
Drop it onto another branch (optionally holding down ⌥ or ⌘) to pull, push, merge, or track a branch.
Create Tags & Branches
You can also drag commits from the History views. Drop them onto the or sections in the sidebar: this will create a new tag/branch based on the dragged commit.
Partially Apply Stashes
When looking at the changeset of a Stash, you can drag one of its changed files and drop it onto the in the sidebar to only apply this very change.
Drag a commit item from the History views and drop it onto the item in the sidebar - this will cherry-pick the dropped commit into your current HEAD branch.