Error to install game made in Unity on mobile. Android

Hey guys the community’s unity. crowd of community unity.

I made a game for android using unity () I made a game for android using unity (4.2) Free. But I’m having problems when it converts and install on your phone. The error says that the application can not be installed. Already followed some tutorials any more. Can anyone give help. Please.

Thank you in advance. hugs

Yes I have the right APi. this all right! I do a tutorial over 100 funcinar anything!

If you can send a link to some tutorial teaching thank you!