[Looking For App] Heart rate monitor with specific requirements

[Asdf178]

Yo,
very simple and to the point requirements for an app, doesnt matter which os or phone, i have yet to buy one for this, but the following requirements need to be 100% met:

i need a heart rate monitoring app that works with some of the newer wrist/arm strap heart rate sensors and allows me to set a minimum and maximum limit and if heart rate drops or gets above my preset limits and stays there for x amount of seconds/minutes that i specify, the app will play a custom soundfile at max speaker volume. No crazy over time heartrate averaging, the errors will be ruled out by the alarm delay, also if it cant find any pulse but the device is still paired correctly, it needs to be returning a zero reading = thus as if heart is not beating and not some sort of "no pulse found" that would bypass the limits and alert conditions.
Its a temporary workaround for a sleep heartrate monitor, the phone will be perma plugged in charger.

thanks for any input (dont bother replying if not 100% sure about your app recommendation)