Useful maps
Level of detail good for Japan. GSI view has English option, but dialogue descriptions for other options in Japanese, so a bit hit and miss. OSM (open street maps) view includes cycling (as available on Cycling Streets and other apps) and transport, which shows railways very clearly (station names in Roman letters), but having JR and other lines in different colours would help. The top RH icon gives useful options including cancelling ads. This is not essential as ads only flash on after a few searches. Beware cancelling payment only works for one device.