The Razer Kishi V2 is a good controller option for Android users looking for a Backbone-like controller with a mostly future-proofed design.
Razer Kishi Review - IGN
Razer Kishi V2 Review - IGN
Razer Kishi V2 review: Making the best even better
Razer Kishi V2 Touts 'Universal Compatibility' and a Subscription-Free App - IGN
Community Review] Razer Kishi v2: Odd Man Out : r/EmulationOnAndroid
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Razer Kishi V2 Review - IGN
Just got a Razer Kishi for my S21U - feel free to recommend some games for me : r/AndroidGaming
Razer Kishi V2 Pro Mobile Game Controller Sends Out Strange Vibrations - CNET
Razer Kishi Review - IGN
Razer Kishi V2 Review - IGN
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Razer Kishi V2 Touts 'Universal Compatibility' and a Subscription-Free App