How to enable unknow sources on Android
When developing an Android application, It’s required to have tested (and get tested) before the application is online on the Play Store and it is imperative to allow unknown sources.
The security system prevents this option by default, so you have to check a box in the settings for authorize this temporarily.
- Menu > Settings > Application or Security
- Check `Unknow sources`
You can now install an .apk file from an email for example.
Be extremely carefully about the source of the application do not install if you do not trust the sender or you do not know what it is!