No, Tower works differently (unless it has changed in the few months since I used it). In Tower, you can select lines by clicking line numbers, but then you must click "Stage" to actually stage those lines. Then your selection is cleared and those lines are moved to a separate "Staged" tab for that file. Whereas with GitHub Desktop, just selecting the lines marks them as lines to be staged. (GitHub Desktop doesn't actually run `git add` on those lines until the moment you click "Commit".)