In 2026, you do not strictly "need" a standalone app to enter Japan, but using the Visit Japan Web service is the highly recommended and standard way to clear customs and immigration. This is a web-based portal (which can be accessed via mobile browser and "saved" to your home screen like an app) that allows you to pre-register your travel information, health declarations, and customs forms. Upon arrival, you simply show a generated QR code to the kiosks. While paper forms are still available as a backup at major airports like Narita, Haneda, and Kansai, using the digital service significantly reduces wait times. Additionally, in 2026, Japan has integrated more biometric "Face Express" technology, which links your digital profile to your facial features at the gate. While not a "mandatory" app in the way some COVID-era trackers were, the digital transition is so complete that traveling without the Visit Japan Web registration is considered a significant logistical disadvantage for modern tourists.