Yes! Using the mobile app, you can download single assets to your mobile device, then open them in the app they were created in or save them to your camera roll. When saved to your mobile device, assets can be quickly accessed and used when you're not connected to WiFi or the internet.
After your download is complete, the apps that are installed on your device will display, as well as a save option. Choose the app to open the asset or click Save Image and it'll be saved to your camera roll.