We support grocery items at Target right now. In the future we'll expand our coverage to include household goods like toilet paper, paper towels, and soap. One non-grocery item that we already cover is diapers, due to popular demand.
Trader Joe's is tricky because they don't have a traditional weekly ad. They do have the Fearless Flier, which includes some pricing information, so we may be able to use that as a source of information. Eventually we'd like to work directly with stores, and if we could do that with Trader Joe's it would be huge.
Whole Foods does offer a list of weekly deals on their website. However, they often use their deals to promote unique / novelty items like salmon candy and "meatloaf cupcakes". If there is enough demand, then we'll add Whole Foods.
Right now we're focusing on the low-hanging fruit of stores that have a traditional weekly ad. The complete list of Bay Area stores that we support is: Safeway, Lucky, Nob Hill, Raley's, Target, Walgreens, and CVS.