My usual device-cleaning method of my sleeve or a napkin doesn't work very well. Even with a micro fibre cloth, you can often just spread your screen grease around instead of neutralising it. Qmadix says its foam busts smudges.
The cleaning foam isn't really something you can pocket, so if you're hoping to keep your phone free of face streaks, you're probably out of luck. But that's a futile fight anyway. Laptops and tablets, on the other hand, grease up easily, and having the bottle in your gadget bag could be a good look. Twenty bucks gets you 60mL of the (aeroplane-allowed!) stuff and two wiping cloths. But how will you clean the wiping cloths? [Qmadix]