I've had likely 9 or 10 Garmin handhelds through the years...but once I found Locus I haven't used a handheld since. That is one well-thought-out app. The amount of configuration options is a little scary at first, but once you get onto it, it's by far the best app I've been able to find for mapping online/offline, saving and organizing tracks and waypoints... Add the map tweak and you can get offline maps from tons of sources... And I really like the fact that it's 2 clicks to back up all your data and upload it to a cloud account and easily restore it if you ever need to. $10 buys a lifetime membership.
For myself, the only thing that's missing is a web interface where you could keep your stuff sync'd and view and manipulate tracks and points on a large screen.