If you need to restore the Handwriting tool as well as any purchased sounds, please go to "Sounds" on the Home page of the app and then "Store." Here you can tap the option to "Restore Previous Purchases." If you tap the icon at the bottom of the page, with a score open, you can also choose to purchase the Handwriting Tool again. As long as you are logged in with the same iTunes account, you will not be charged again. You may also want to make sure that you are logged into the same Apple Account that you used to make your original purchase of the sounds as well as the Handwriting Tool.