FIIL provides an App for Android and iOS: the FIIL+. Here with FIIL CC NANO
A nice detail of the CC NANO case is the LED that indicates the operation of the case
This LED also indicates the battery status of the case when you put the earphones back in the case
The earphones have the indicative LEDs on the top of the stems, it is through them that we guide ourselves when the earphones are receiving charge (energy from the case).