Use APKPure App
Get Call Flash Alert old version APK for Android
आने वाली कॉल और एसएमएस पर फ्लैश चेतावनी
If you want to know the incoming Call or sms in dark .Call Flash Alert app will help you.
when incoming call or incoming sms,the camera flush start blinking
Just check the checkbox on incoming call or incoming sms or both.
You can share this app to your friend also.