Amazon offers its VicTsing 3-in-1 Clip-On 180 Degree Camera Lens Kit for Smartphones and Tablets for only $9.99 when you apply coupon code 8S7NMHUX at checkout. Shipping is free on orders over $49 or Prime. They feature 0.65x Wide lens+10x Macro, light-weight and beautiful aluminum alloy shell, blue tape plating and flexible adjustment design.

Note: Walmart has it for $19.99.