It is possible. Yelp is pretty aggressive about driving people to download the Yelp app, though. Even when you follow a mobile web link of the format m.yelp.com/biz, you're still prompted with a big button to "DOWNLOAD THE APP", or in small gray letters: "[SUB]Continue to mobile site[/SUB]"
If you choose to continue to the mobile site, you can still write a review via the browser. Of course, Yelp benefits big from maintaining a functional mobile site that is well-indexed and gets a lot of traffic from search.
Testing this on our battery of actual iOS and Android devices this morning (not emulators), Yelp does force the app download at the point you try to enter a rating or review when you follow the standard path above.
New advertising option:
A review of your product or service posted by a Sterling Sky employee. This will also be shared on the Sterling Sky & LSF Twitter accounts, our Facebook group, LinkedIn, and both newsletters.