Reasons for the application not being installed
1. The software signature is inconsistent. This situation usually occurs when updating software. For example, if you have installed an older version of a certain software before, and the signature of the software you need to update is inconsistent with the software you have installed before, the application cannot be installed.
2 The software is not signed. This situation usually occurs when you extracted the software from the ROM package or modified it yourself without re-signing it.
3 The system version required by the application is different from the version of your phone. For example, a certain mobile phone software requires the Android system to be Android 2.3 or above, but the Android system of your mobile phone is Android 2.2. It will appear that the application is not installed.
Method
In the case of inconsistent software signatures, you need to uninstall the old version first and then install the new version. Go to phone settings → Application settings → Manage applications → Click on software → Uninstall
For unsigned software, this requires a signature software, Baidu zipsigner, install this software, open it and sign the required software. 1 shows the software that needs to be signed; 2 is the place where the signed software is saved; 3 here you should pay attention to changing signed.zip to software name.apk. For example, if you sign QQ, it will be mobile phone QQ.apk. Mainly for convenience Find out. 4 is the start signature. After completion, go to the directory you set to find the software and start installing it
For insufficient system requirements, you are Android 2.2, and the software requirement is Android 2.3 or above. You can only find out if there is a lower version of this software, or upgrade the system.
If you are a computer friend who has obtained root permissions, there is another way to install unsigned software, which is to place the software into system/app through the root file manager and change the permissions to as shown in the figure. Just show it. Remember to click on Read and Write in the upper right corner, and then restart your phone.
Also, you can sign on the computer, but you need to set up a java environment. Please use Baidu.
Then search for apksign, download it and sign it directly