By downloading the Forever 21 app, you'll gain access to the same range of products and items as you would on the website version, as well as the ability to control your account, returns and customer service queries. One benefit is being able to do this from your phone and wherever you are with an internet connection. Another benefit is that certain coupons are specifically related to app purchases, which can only be redeemed on your phone. You can download the app on both Apple and Android devices for free.