The Speedybee app is the best Betaflight Smartphone App I've ever seen. It's got about 80% of Betaflight Configurator functionality built in. It's good looking and pleasant to use.
Combine the Speedybee app with the Speedybee Bluetooth adapter and you don't even need a USB cable. It's even got a function where it turns off Bluetooth when you arm, so it doesn't interfere in the air.
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