The Snaps extension is no longer accessible via your projects home page. Until October 15th, 2017, you will still be able to see all your previous snaps and create new ones by visiting:
If logged into an Enterprise account, replace projects in the URL with your company subdomain. For example, https://companyname.invisionapp.com/d/main#/snaps
We are currently working on the best solution for users who want to share single images for quick feedback. In the meantime, we recommend you create single-image prototypes, or upload individual screenshots to a board so you can share across your team.