UNIQLO IN is a free iPhone app developed by UNIQLO CO. LTD. that allows you to shop conveniently for your favorite clothing items and accessories. The app offers exclusive prices for members, as well as access to designs and sizes not available in stores. You can also shop for extra sizes, from XS to 3XL, or online exclusives.

With UNIQLO IN, you can join special promotions either online or in the store through the app. You can also choose from a range of delivery options or pick up your order in store. Additionally, you can read customer ratings and reviews to find out what other shoppers have to say about products' design, fit, color and more.

Overall, UNIQLO IN is an excellent app for those who want to shop smart and conveniently for UNIQLO's clothing and accessories.