The beautiful advantage of traveling in a Camper / Motorhome is the ability to be independent. Whenever you meet local people or travellers who give you travel advice you can choose to change your route. In the winter time when the sun is setting early it is very useful to know where to camp instead of trying to find a suitable camp ground in the dark. This allows you to spend as much time as possible on activities before choosing a campground.
There are some really good Smartphone-Apps, which are constantly modified and extended by user content. Everybody can post information about the quality of campgrounds, the availability of toilets, but also scenic sunset spots, free Wi-Fi zones or walking tracks. WikiCamps, Rankers and Campermate are very recommendable. Users can comment on topics as well which is a good indicator for the quality.
The maps can get downloaded and then used offline, so no mobile data will be needed while traveling.
Campermate can also be set up in different languages like German.
Tourism New Zealand developed an App which lets you create your personal travel route and you can highlight destinations you'd like to see on the way. It is called 100 % Pure NZ.
Also Global Campers has an App with lots of useful information about destinations, there history and description of attractions.