What is the meaning of SIGN and UNSIGN?
Signed apk >> for non rooted device + can not login to google account
Unsigned apk >> for rooted device + can login google account
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Note (~unsigned)
Even if you have root, for install unsigned apk you still need to do this steps

using (Lucky Patcher

)
-
DISABLE APPLICATION SIGNATURE VERIFICATION USING LUCKY PATCHER
1- Open Lucky Pather
2- Tap on "Toolbox" -> "Patch to android"
3- Check "Signature Verification status always true" and "Disable .apk Signature Verfication", then apply changes. After this maybe your Android device will reboot automatically. If your Android device not reboot automatically, continue to the next step.
4- Still in the "Patch to Android" menu, check the "Disable signature verification in the package manager". Apply changes, and done! (May reboot automatically)
5- Done, Now u can uninstall luckypacher then install file apk unsign
6.Enjoy MOD !!!