When you first install the app, your smartphone will ask you if you want to allow access to certain features of your phone with the app:

Bluetooth activation
This activation is mandatory to control the bulbs from the application because the bulbs use Bluetooth technology

Localization activation
This activation is not mandatory on iOS, but it is on Android since version 6, in order to detect devices with Bluetooth technology.

Notifications activation
This activation is not mandatory. But this setting allows you to update the configuration of the bulbs in real time on all smartphones connected to the same user account.