Wireless sound monitor on android tablet

Hi, I'm starting this project and would like to know from you if I'm on the right track or not?
25x KY-038 sound sensers
Arduino with nrf24l01
Android app that displays 25 lights-
green when noise
red when silent

I can't seem to find anything on creating a android app as a display for what state the sensors are at besides serial displays (not what I want). Only to use app as a remote?

What other Arduino/nrf24l01 will this communicate with?

If one can control, for instance, a stepper motor a arduino, with a app on my phone, can't I retrieve data from arduino with phone and display it on a app?

Sure. Not with an NRF24

Okey, so either use a Bluetooth module - hc-06
or use 2x arduinos with 2 nrf24l01 and some led and build a display monitor