Whilst I rarely use the apps for finding caches, I have the iGeoKnife app https://itunes.apple.com/us/app/igeoknife/id463856852?mt=8 on both iPhone and iPad. You can of course use this to find caches and on the couple of occasions I have used it I have found it to be very accurate (running on iPhone 4S).

More importantly for me it enables me to view all my GSAK notes out in the field about caches I intend to look for (especially all those puzzle caches) rather than having reams of paper in the rucksack.

This is even better now as the satellite images now use the google ones again, but I don't know if this is due to me having the google maps app installed?

Please be aware that it is all off-line data though, you have to load your GSAK databases onto your phone. I have a not found database (some 32k caches and growing!) and I also carry my found database, as quite often whilst out in the field I fancy navigating somewhere and remember a cache I have found that was near where I need to go, I can quickly get the co-ords from the phone and enter them in the sat-nav, this is great as usually when you need information there is no 3G signal so cannot connect to the live database!

There is another app I have used on the odd occasion, Geocaching Toolkit https://itunes.apple.com/gb/app/geocaching-toolkit-igct/id290585562?mt=8 which has a free version, it enables waypoint projection and a few other conversion tools.