First thing's first: THIS APP REQUIRES NO DATA TO FUNCTION. No matter how many people I talk to, someone always pops up to complain that it won't work when you're out of cell range. I state now, once and for all, when you're on the road, this requires no data. Some of the additional features may, and you must download the mapsheets ahead of time, but all you need for this to work in the field is the GPS chip--which every cell phone has. Best part? Try it for free. In the free version, you can download up to 10 mapsheets--which may be enough for you never to upgrade anyway, since each is a state or country. If you do choose to upgrade to the full version, the cost is around $8--probably the best money you can spend on navigation. Half the time, I can't buy paper maps for that much. This app has a million features, but here are the ones I really like: - it's more versatile than my Garmin 650t. It'll load anything GPX without a hassle. - It will save GPX (many configurations possible for intervals and other info), though I've actually had better luck with Google's My Tracks for pure simplicity. Often, I record using My Tracks, then export to GPX and open in OSMAnd+. - pinch and pan using the phone interface is awesome - Bluetooth allows turn-by-turn instructions on your helmet headset if you're on the road - A $2 contour plug-in gives you topo capability (download a small topo overlay for each regular mapsheet). If you don't know how awesome this is, save your $2 for a half a cup of coffee at Starbucks. - It actually doesn't draw much power. My phone will last all day with it on while recording GPX tracks. The display is what sucks battery. My phone (Droid Razr Maxx HD) will run OSMAnd+ longer than my Montana 650t will run on a single charge and the display turned all the way down. - You can load it onto a full-sized tablet or a mid-range 7" "phablet" and have an enormous display. Some of these new phablets are actually waterproof (Sony Xperia is one) and have batteries to go for a really long time. Try that on your GPS. - My favorite capability is setting an overlay map and selecting Microsoft Earth. This gives you an overlay on top of the base vector map and a slider to choose the transparency. This is hugely useful for seeing things like clear-cuts (logging is big up here in the PNW) or finding paths and trails that aren't on a map. This feature alone is worth the $8. It requires data of course, though you can preview the places you're looking at from the comfort of lunch or home wi-fi, and the imagery will remain cached. I've used this for elk hunting, and it's very slick. Drawbacks: - there's so much here, it's intimidating at first - you have to save the mapsheets on your phone. Some are pretty big and will take a while to download, as well as a lot of space. - I often have trouble getting it to navigate to a street address. When using grid coordinates or picking a spot on the map, it has no difficulty at all. - Check your settings for what the phone enables during low-battery mode. Mine was set to disable the GPS chip. - Yes, your phone is probably not as hardy as your purpose-built GPS. Yes, the screen is probably less well-adapted to direct sunlight, and charging can be a challenge due to vibration, even if the tablet or phone is waterproof. Yes, the screen might not work with gloves (there is a glove treatment you can use for this though).