We "discovered" Snack Mahana while looking out of the shuttle bus from the airport to our resort. We asked our driver about it and he said it is a good place to eat and a nice walk from our hotel (it is about 3/4 mile).
We also confirmed with another local that it is a good place to eat, AND they will accept US dollars at a rate of 90 Polynesian French Francs (XPF) per dollar. This is much better than the 82 XPF plus a transaction fee that our hotel would have charged us. Snack Mahana only takes cash.
Before I go further, a disclaimer is in order. Although we enjoy upscale restaurants, some of our best dining experiences have been at what we call "joints". These are usually small places that don't necessarily look pretty, but are locally owned and have amazingly good food at a relatively low price. Snack Mahana qualifies as a "joint".
It was a very windy day, so we sat inside. We ordered the local beers (Hinano and Tabu), a burger with fries, and a steak dish with salad. The burger was cooked properly and the lettuce on the salad was fresh. The steak was perfect.
Service is very friendly, but you should allow about an hour or so for your visit. Given how much we enjoyed being there and how relaxing it was, speed wasn't an issue for us.
Food at Snack Mahana costs about 20% less than at other modest sit down restaurants on Moorea, yet our meals were excellent. It is worth a visit, and if it isn't too windy you may want to consider one of the outside tables, which have excellent views of the ocean.