You have to get the application signed first, or you can go through the installation unsigned application. Do you need to know how to make it? First, you can hack your phone (it is not recommended). Next, the second one, you can remove the ‘signed’ restriction by getting a certificate and key your phone. It is possible to sign each application individually.
You can sign the application by visiting cer.opda.cn, which is a site to help you process your certificates and it is a free service to access. What you need to do is just register for an account and click “Apply Cer” when you have logged into the site.