Thanks for creating and maintaining the best Geocaching app out there! Can't wait for the 2.1 version!
Similar to the UK's Ordnance Survey, Norway has an official mapping agency called Kartverket. They provide various high quality mapping services for free to end users and developers. Among them are a tile service using the Google Maps API specification, which may be integrated into apps free of charge. There is a generous restriction: Each app end user (based on IP) can only download 10 000 tiles per day.
More details here (Google translated): https://translate.google.com/translate?sl=no&tl=en&js=y&prev=_t&hl=no&ie=UTF-8&u=http%3A%2F%2Fwww.kartverket.no%2Fdata%2FAPI-og-WMS%2F&edit-text=&act=url
An example webapp utilizing the API, with different layers: http://www.norgeskart.no/#!?project=seeiendom&layers=1002,1014&zoom=10.896666666666663&lat=6761526.53&lon=-28642.01
License and attribution (Google Translated)
"Mapping free products licensed by Creative Commons Attribution 4.0 International (CC BY 4.0).
This means that the name of Kartverket shall be displayed in all contexts where the products or extracts thereof are used, such as applications, web solutions, printed products, illustrations or other, as follows: © Kartverket. It should also be linked to our websites (www.kartverket.no) where this is possible."
If possible, it would be great to have the ability to use these high quality maps in Cachly! Norway have a vital caching community, and with 76.000 caches we are currently ranked as nation #7 worldwide. And hopefully, the ability to show the official maps would bring in a lot of new users to Cachly.
Thanks again for creating the best cache app out there!