Making Insta360 One R & One X audio recording better with a mobile app

[supercurio]

The Insta360 One R and One X are some of the best cameras to record videos of our EUC adventures, however capturing good audio and clear voice without adding an expensive and complex setup seems difficult. 

I'm about to get my hands on a One R and hope to build a better solution.
The idea is to start/stop recording audio with your phone in sync with the camera activity.

Potential input signals:

• built-in mobile phone mics
• 4-pole JACK analog external mic
• USB microphone (could be stereo, maybe multi-channel)
• Bluetooth headset (for processed voice only)
• Wireless microphone, connected to the mobile phone instead of the camera

Benefits compared to wireless audio transmitter/receiver on the Insta360 One R:

• No added weight on the camera
• No need for the extra ONE R Mounting Bracket with Cold Shoe Top Mount ($30)
• No need for the extra USB-C Mic adapter ($10)
• Camera remains waterproof!
• No need for an extra wireless microphone system

Downsides compared to wireless audio transmitter/receiver on the Insta360 One R:

• Requires replacing the audio when editing
• Requires doing some (minimal, likely automated by the editing software) audio sync

Benefits compared to manual external recording with the Insta360 One X:

• Simplified audio sync when editing
• Avoids content loss from operation error
• Carefree feeling from pressing a single button to record 😄

I'm a senior Android developer and if confirmed feasible I should be able to prototype this app pretty quick on this platform but I wonder how many of you would need an iOS version instead?

Note that it might be more convenient to run the app and plug the mic to an old spare or $99 Android phone for cable management purposes.
It's not uncommon to use the single (USB-C) port of a phone to charge it while recording a ride on EUC World for instance, then the port is unavailable to plug the mic adapter.

I know I now need and will use this app instead of buying $200 of extra gear, so I'll try to build it.

Anyone else is interested? 👋
Would you need it for iOS or Android only is fine?

Edited September 4, 2020 by supercurio
Added downsides section