New Gmail touch app released. It's not an official Gmail app, and there are no notifications or live tiles (yet), but it works much better than navigating through IE.
The official google app is in the MS Store, it works well for most of the google services, including gmail and youtube.
Yes, check out the search app. there is a button on the bottom to access Google apps. it's not exactly a dedicated gmail app but it's more convenient than just using IE.