i need app for apple watch simple heart rate thats it, i need fast and efficient coders no time wasters!!

This watch app must monitor the heart rate sensor during sleep and after going over a certain BPM, the watch will start a vibration alert to wake up the sleeping user. The user can switch between sound alert or vibration alert. I don't need any special logos, icons, nothing. This is just a proof of concept. This is for when the user is having a bad dream.