Demi Lovato posted her last YouTube video as a 15-year-old on Tuesday (August 19). The ‘Camp Rock’ star, riding in her tour bus, talked about the 5-week countdown before her debut album ‘Don’t Forget’ is released, the release of her ‘Get Back’ video on Friday after the ‘The Cheetah Girls: One World’ premieres on the Disney Channel, and “having a lot of fun playing shows” with the Jonas Brothers. Watch the message below.