All arriving visitors to Japan are required to download all the phone app provided below to ensure strict compliance with the 14-day stay @ home/accommodation quarantine rules of the government. It is advisable that the passenger has downloaded the apps prior to arrival in the country.
If you do not own a smartphone or if you own a smartphone that does not allow the installation of apps, please rent a smartphone at the airport at your expense upon arriving in
Japan.
For more details, please check this link.