Finally, an awesome official betaflight release for Android! With all the features of the full betaflight application, you can now have a complete betaflight solution on the go on your mobile using OTG support!
To download the betaflight configurator for Android, head over to the GitHub releases page and download the Android APK file. If prompted to allow unknown sources for installation then allow it and continue the installation.
https://github.com/betaflight/betaflight-configurator/releases
All that is required is a USB OTG cable, this allows you to plug a standard USB cable into your phone and plug in USB devices, including a keyboard and mouse. USB OTG cables come in different types, MicroUSB, TypeC etc. Below are some examples of OTG cables and are widely available for purchase.