Some our themes are designed to allow you to display your latest tweet in the menu.
Make sure you are in your dashboard and have the right blog selected, then click the cog icon to go into your settings.
1. Look for the 'Share on Twitter' button
2. When prompted authorize Tumblr to use your Twitter account
3. That's it! You can also turn on the option to 'Share posts on your Twitter' or 'Log out' if you so wish.