Once you've created a project in the Seenit Studio you can invite people to download Seenit Capture and issue them with a project ID (a password you create during project setup). Once they enter the project ID they will be able to see your project and film for it. Anything that's filmed on Seenit Capture is then stored in your Studio for you to review and use. You can also send messages to Seenit Capture users.
Here's a short video on how it works that might be useful to share with your contributors.