Since I have been asked (in other forum, etc.) how these compare to Fly Grip, you can checkout the whole write up and pictures in my signature link (for Fly Grip).
To be honest they serve a similar function. Both will help you to get a better grip on your phone with one hand, but one has a hard plastic latch that sticks out more from the case while offering a more comfortable grip and also converts in to a kick stand, while the other one is a very low profile elastic band attachment. There is also a significant price difference. There might be an issue with FlyGrip if you want to use car mount, while Sling Grips can either be used with a typical car mount or it's own car mount. Also, Sling Grips offers easier in and out of the pocket and more stable when phone placed on the back screen up. I really do believe these two are like apples and oranges and some will prefer one over the other.
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of all smartphone and tablet Accessory and Gadget REVIEWS by Twister