Gaia GPS v6.6 for Android introduces Snap-to-Trail routing mode and includes a big improvement to how statistics get calculated for recorded tracks.
Automatically Route Along A Trail
Snap-to-Trail routing lets you plot a route along any trail using OpenStreetMap based maps like Gaia Topo and OpenHikingMap HD.
Choose between 4 different routing modes: hiking, cycling, driving, and manual. View a live elevation profile as you create your route and change your map layers during routing to help with planning. Easily toggle between Topo and Satellite Imagery, or other map sources.
Advanced Track Recording Statistics
Improved statistics for track recording gives you more accurate measurements and improves accuracy of statistics on the website, too. To read more about the statistics improvement, read this blog. Please note that statistics in the app may still vary slightly between the Android app and website, but they should be pretty close – the website and app use the same underlying data, but slightly different algorithms right now.
You can read the full release notes here: http://updates.gaiagps.com/android/android_6.6.0.html