There isn't anything that makes couponers more angry than spending a long time matching coupons to sales for maximum savings, and then being told by the cashier that the coupons won't be accepted. Therefore, keeping an eye on grocery stores' coupon policies is essential before you shop, and the same is true for mobile coupon policies, which can differ from paper coupon rules.
Stores ranging from Schnucks (which offers "Schnupons," as seen above) to Target (which has its own Text Alert club) allow you to save money using your mobile phone while picking up your groceries.
If your store is still hesitant to accept mobile coupons, you should talk to the manager and let them know how you've been saving with your cell phone at other markets. That way, the store might be more persuaded to also accept mobile coupons in order to compete with other local grocers.