Yes. You need a Dropbox to use Carousel because all your photos and videos in Carousel are stored in your Dropbox account. It keeps your photos and videos safe and make sure they are protected. If you have already a Dropbox account, then simple sign into the Carousel application with your login. If you are new to Dropbox, then first you need to download and install Carousel app on your device. When you download the Carousel app on your device, you can immediately get started by selecting "Create a Dropbox" option.