How I Simplified with A Stick-On Wallet Yes, a credit card wallet attached to my phone has made my life simpler and I’ll tell you why! What Is It? All it is is a silicone sleeve that attaches to the back of your phone or phone case with adhesive. It’s large enough for 2 credit cards, or, as in my case, 1 credit card and a driver’s license. But also snug enough that your cards won’t fall out!