In some cases you are downloading Android app or games from a third party site other than Google play store, then you may find that the application is not installing on your device, and your smartphone is throwing an error: ‘X Application not installed‘.
This can be because the modders want to keep the original signature so that the modded app/games will work normally.

What is the difference between SIGNED and UNSIGNED apk?

There is only a minor difference in both the version of the application. The signed app contains an extra folder i.e. ‘META-INF’ which also contains the following:

• MANIFEST.MF
• CERT.SF
• CERT.RSA

1. Install unsigned APKs on ROOTED phones?

1. The very first thing, of course, you need to do is to root your android device.
2. Download and install Busybox.
3. Then Download and install Lucky Patcher.
4. (Lucky Patcher is a wonderful application which can be used to hack many applications/games, block ads on any android device with/without root).
5. Now Launch the lucky patcher app and wait until it gets refreshed.
6. Now, a menu will appear where you can see your installed applications. Then tap on ‘Tool Box‘: 
7. Now, a pop up menu will appear. Tap on ‘Patch to Android‘: 
8. Now tick on the “Signature Verification status always true” and “Disable .apk Signature Verfication“.
9. Finally, click on Apply.

That’s it!

2. Install unsigned APKs on UNROOTED phones?