Luckily with a smartphone or tablet we have a tool to help us out on our travels. I would like to introduce you to the must have apps, including offline apps, for a smooth trip in Japan. Feel free to introduce more suggestions in the comments below.
This is a great app for finding your way around. My favourite feature is the neighbourhood guide to find an ATM or convenience store. One of the best options for sure is the OFFLINE search for free wifi spots.
This iOS offline app is the best for finding your way around town without a wifi signal. Doesn't show train times though so be careful when it is close to last train.
The best website for train travel planning now has an app too! One of the best features for those using a JR pass is you can filter results to include JR trains only. All the info you need to get around Japan by train.
This site and app is famous amongst Japanese and they now have a great English version too. Find restaurants by type, price or even by GPS search. They even offer a restaurant reservation service hotline.
There are many to choose from but for me the best ones are useable offline too. That's why I like "imiwa" for iOS or JED for Android
This is an app and website which has many mini guides to tourist attractions not only in Japan but around the world.