DeftunBluetooth MSR-X6(BT) MSRX6BT Magnetic Stripe Card Reader Writer Encoder Mini Portable

I plugged my MSR into the wall to charge it and it’s blinking red and green fast, does that mean it’s charging ?

iOS app that's 20$ is no longer available on the apple store?

My reader was working fine, now all of a sudden it doesn’t connect to the app, i plug it up but no charge, adapter and computer?

what's it the "Must download the $20 dollar app"?