List of restrictions below. Works both in store and online. The in-store does not block jeans, which most of GAP's coupons do, so I'd recommend that.
Restriction list: Offer valid from 7/9/2017 at 12:01am EST to 7/10/2017 at 11:59pm EST online and at Gap, GapBody, GapKids, and babyGap stores in the U.S. only (including Puerto Rico). Offer not valid at Gap Outlet, Gap Factory stores or Gap Factory online. Not valid on international purchases. In store discount applies to Gap-branded products ONLY and excludes products that are not solely Gap-branded products. In store offer excludes markdown styles, babyGap First Favorites, babyGap Garter collection, Sculpt Compression Leggings, and leather and suede apparel. Online offer is not valid on the following regular price Gap merchandise: Jeans, Technical Denim, Baby Organics Collection, Kids and Baby Shoes, GapBody Underwear, Baby First Favorites, babyGap Outfit Box, Kids Backpacks, Lunch Bags and Wallets, Cashmere, Leather and/or Suede Apparel and Accessories, Maternity Ingrid & Isabel®, Noodle & Boo®, Clarks®, Free City, and Alex's Lemonade Stand. In-store prices may vary from online prices. Offer not applicable to GiftCards, packaging, shipping & handling charges, taxes, prior purchases or telephone orders placed to stores. For items offered at both multi- and single-unit prices (e.g., buy one for $5, five for $20), discount will be taken off single unit ticket price. May not be combined with other offers & discounts except for Rewards, online only with The Summer Sale, and in stores only Everyday Plus Up offer and the initial acquisition discount when approved for a new GapCard. Offer is not transferable & not valid for cash or cash equivalent. Online: enter promo code at checkout or tap to redeem on mobile when available. In store: enter promo code at checkout.