Yelp has a Windows phone app. Even if it didn't, you can do that from a web browser too.

Regardless, the point stands, WP7 receives a lot less app attention - which makes sense since it has 1.7% market share.

For example, the new Angry Birds launched on iOS and Android, and has no plans to port to WP7 due to the need to rewrite it for that platform,

http://www.bloomberg.com/news/2012-03-22/-angry-birds-space-...

This point would be valid, save for the fact that there a Yelp app on WindowsPhone.

There is but you can't do anything useful with it like login or submit reviews.

Yelp has a policy that bars reviews written on mobile devices. This is done to protect the quality of the reviews.

You can't submit reviews from an iPhone either. The functionality doesn't exist.

In Android, you can submit reviews written via a browser, just not via the Yelp app. Via the app, you can write and submit "quick tips" (which are often short reviews) and draft regular reviews with a star rating on your mobile device, but then you have to open the browser to submit them.

Are you just making this up? I just did that with my iPhone Yelp app right now.

Go to a yelp entry, "Add" and "Draft a review".

Alright, you can't login to the Yelp app then.