caltrain

What you are asking for is a timer. Not an app. https://www.amazon.com/Uigos-Digital-Kitchen-Magnetic-Backin...

Unrelated: Elon Musk was on H-1B before Paypal days.

Great read

Truck's color can not be part of the plot, its a B&W movie!

Quick example why its not supported: Lets say you are building an instagram style app. You need to render an image from network and won't tell the app its vertical height(Just like you would do in a webapp)

The app has to judge the image height after the image is finished loading from the network. If the second image loads faster than the first image, then UI has to push the second image further below to make space for the first image. This will make the app look jittery.

SMS Read: You can start with manual entry of phone number verification. Top of the line android and iPhone apps still use manual entry of verification code and still offer good User Experience.

NFC: Except for payment, I never used NFC for anything, never seen any of my friends use it for any practical purpose. If your app is using payment systems, forget react native.

GPS: Supported by React native.