Vansky Waterproof Phone Case, $6 with code 39DZSJ6Q

Water-resistant smartphone bags are a must for any trip to the beach, if only to keep the sand off your screen, and this $6 model from Vansky even includes a passthrough headphone jack, so you can listen to music or podcasts while you lay under your Sport-Brella. And if you do take it into the water, it also floats.