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 that needs to be updated is inconsistent with the software you have installed before, the application cannot be installed
2. The software is not signed. This situation generally occurs when the software is extracted from the ROM package or has been modified by oneself without re-signing.
3. The system version required by the application is different from the version of your mobile phone. For example, a certain mobile phone software requires the Android system to be Android 2.3 or above, but the mobile Android system is Android 2.2. It will appear that the application is not installed.
Solution
1. 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 Software → Uninstall.
2. For unsigned software, a signature software is required. After opening it, sign the required software. After completion, go to the set directory to find the software and start the installation.
3. 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.