Suica (Apple Wallet / Google Wallet)
Free to create; load what you need
One tap for every train, subway, bus and convenience store in the country, with no physical card to buy.
Before you fly
Japanese transit data in Google Maps is close to perfect — platform numbers, car numbers and exit names included.
Before you fly
Japan Transit Planner (Jorudan)
Free; paid tiers add features
Better than Google Maps for Shinkansen planning, seat classes and fare breakdowns between rail companies.
Pre-registering immigration and customs turns the arrival queue from 40 minutes into 5.
Before you fly
Japanese menus, station signs and pharmacy labels become readable through the camera.
Before you fly
JR East / Smart EX (Shinkansen booking)
Free app; tickets at face value
Reserve Shinkansen seats from your phone instead of queueing at a ticket office.
Airalo / Ubigi (Japan eSIM)
From ~US$5 for 1GB / 7 days
Japan has little free public wifi outside stations and cafés — you need your own data.
Before you fly
The restaurant ratings Japanese people actually use — and the scale is different from Google.
NERV Disaster Prevention
Free
The fastest earthquake and tsunami alerts in Japan, in English, seconds before the shaking.
Wise / Revolut
Free account; ~0.4–0.6% conversion
Japan is cash-heavy, so ATM withdrawals are frequent — fee-free withdrawals add up fast.
Before you fly
The default messenger in Japan too — hotels, tour guides and restaurants use it.
Before you fly
Booking.com / Rakuten Travel
Free app
Rakuten Travel has Japanese inventory — ryokan and business hotels — that international sites miss.