You can now set up a full approval process for your internal teams or external partners using the Filestage - Asana integration.
With this integration you can review and approve all kinds of digital content: images, video, documents, audio and live websites.
Sync your projects in a few clicks so you can assign review tasks, set due dates, and keep your Filestage approval process moving forward in Asana.
Filestage has also free plan to start with.
More on the integration here: https://asana.com/apps/filestage