What is the invoxia app used for with the Audioffice? Invoxia November 18, 2015 10:29 Updated The invoxia app is to be used with the Audioffice to: - update the device firmware - and access the sound settings. Related articles Updating your Audioffice. Check your coverage Assemble the NVX 620? View your trip history Does the invoxia NVX 220 phone works via Wi-Fi?