The idea of a suction cup to hold my smartphone looked liked me a lot a long time. I set my heart on this. If I play a lot with 5 cups, they have instead tend not to last long. Often she takes off after twenty minutes. On a perfectly smooth surface, it seems to take better, but let's be honest a smartphone is never completely smooth. I would recommend the product EBEST3,5 mm Headphone Jack Audio Splitter Suction Mount for iPhone 4.