NightscoutFoundation/xDrip ? reverse-engineered prompt

Build me an Android app like xDrip, a personal diabetes data hub that can connect to glucose devices, show readings in a clean graph, and help with day to day treatment tracking.

I want it to support entering insulin, carbs, and notes by voice, keypad, or watch, and to show insulin and carb action curves with undo and redo. It should have strong alerting, including predictive low warnings, and be able to sync data instantly between phones and tablets. It also needs to work with common CGM and glucose sources, plus support watch based data and display where possible.

Please include a polished settings area for customizing alarms, display options, and voice behavior, and make sure the app can export data and talk to other health apps or services like Nightscout. If anything is unclear, look up current device and Android docs online and make practical choices that fit a modern Android app.