I use this Gamesir X2 because it's one of the few controllers with the USB connection in the lower left which means folding phones open up, like a DS. Otherwise they open down and the screen is below your hands and it's kinda weird.

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Oh this is nice…. What are you using it with? Is that a tablet?

Smart choice, The Gamesir X2's design definitely makes it a great option for folding phones.