Not shipped yet. The Xcode project, the entitlements and the iCloud storage backend are already in the repository - what is not there yet is a build in the App Store.
You do not need to wait to read a review on your phone. app.dev.review already runs in mobile Safari, and three of the five storage backends need nothing a browser cannot do: a GitHub repository, a git remote reached through a proxy, or an S3-compatible bucket. What is missing without the app is a folder picker and iCloud Drive, which is the gap this page is about.
An iPhone, and iCloud Drive turned on for the app - the same storage every other iOS app that saves to iCloud already asks for, nothing dev.review-specific about it. There is no folder to choose: the container is fixed by the app's own identifier, so attaching it is one tap rather than a picker.