I have a huge amount of experience in a short time with an Android-only app called GPS Orienteering, $6 from Google Play. It's been, along with karttapullautin, the mainstay of my entire short and torrid love affair with orienteering.
When not buggered up by user error, it works perfectly.*
All courses on my baby club's RG have been run using GPSO, and I've turned a number of friends into similar fiends, sending me triumphant screen shots of their very first custom GPS courses.
Don't get me started. I'm utterly obsessed with the infinite possibilities this technology unveiled (imho.) Find me on Facebook and I'll add you to our group for pics and such.
Here is my RG and RG2, depending on your preference.wncoc.org/gadget/cgi-bin/reitti.cgiwncoc.org/gadget/rg2/
Happy to answer any specific questions, and I am not affiliated with the (very nice and responsive) developer.