Mi Security App size is 38MB and the latest version is 5.0.2 (Updated).
You can download the App from Google Play Store or from Xiaomi Inc. official website for free.
We are strictly not providing any mod/cracked/patched apk.
Click on the Download APK (38MB) on below section.
You will be redirected to our Secure Download Page or Xiaomi Inc. website.
Save the com.miui.securitycente .APK file on your Android mobile/tablet.
Turn on "Unknown sources" from Settings -> Privacy -> Unknown sources
Open the .APK file or Mi Security.apk from your mobile (Download folder).
It will prompt for Install, click Install and follow instructions.