A beginner guide for Sending data from android app to nrf52833BLE like sending a button status from android app to nrf

I have seen webinar on YouTube where  NordicSemiconductor demonstrated a peripheral_hr that send simulated heart rate data from nrf52833 to nrf android app. But now I want to send data from an android app to the nrf52833. For instance I want to send status of a button (0 or 1) from android app to nrf52833. Is there any straight forward or simple resource available anywhere on internet to do this simple thing?