Having used a number of mapping apps I have settled on google maps as being the best – always up to date maps and the most comprehensive up to the minute traffic / delay data. Also have Here maps and Navmii installed for fully offline use if required (ie no signal).
I use Navmii, used to use Here, I also have CoPilot, Apple Maps and Google maps on my phone. Navmii gives me live traffic updates on the fly with route update, it gives me three route options on setup with time differences, and has only had issues a couple of times when the app has locked up, but seeing as how I use it every day as part of my job, and it’s so far logged nearly 15000 miles* since mid-September with minimal issues, I’m happy to carry on using it.
*Actully done a few thousand more than that, but not all journeys need the satnav.