When connected to the Earin App you are able to update the firmware on your earphones.
You will get a push notification when an update is available and all you have to do is follow the prompts.
Here is quick video on how to update firmware on your Earin A-3 Earphones.
In the settings menu, you are able to see what firmware version your earphones have.
During a firmware update your earphones can still be used as usual.