I mostly use Google maps but I have occasionally been caught out when there is no coverage (yes I know you can download areas). Anyway yesterday I tested the IoS version of an app called Sygic. It cost about £12 for complete UK coverage. First impressions are quite favourable. Google will probably remain my first choice but it's good to have a fallback for planning routes offline.
What offline system (if any) do you use?
What offline system (if any) do you use?