Geocaching App on iPhone4s is very good. The unit is very fast and many times when I jump out and head for a cache, I leave my PN-60w in the Jeep in the RAM window mount and just use the iPhone4s to navigate to the cache. If I have cellular data, it's great with the Google quality maps. I find it to be rather accurate....for a smart phone. I'd never use it to place a cache for for caching on a long hike. But what I like it for is when I place a cache and am unsure if another cache is too close to my location, I can do a quick nearby search including caches I have found. It also has a great advanced search feature which allows you to be selective about what types of caches you filter, and even filter out caches found by someone else which is nice for Geocaching with another cacher who may have already found a nearby cache. I also on long trips ahead of time download at home from Geocaching.com through the App, my PQs that I'll be using. I came in handy on my Northern trip doing my Delorme Grids. Even though I rarely had cell service, the GPS was on and I could access cache info in a more readable manner than on the PN-60w. I especially like the App for reading legnthy cache descriptions like on a puzzle cache or even more so, an Earth cache. Then I put my answers into a note on the app and/or upload a field note and it's golden. I love it for logging random caches and for FTFs. You can visit TBs with it into a cache find, add favorite points, and upload a photo with your log. You also can log new Trackables that you find, discover or grab too right on the phone. It's a great App except for placing caches. Please NEVER place a cache using an iPhone or a smart phone of any kind. Stick with averaging your cords with a hand held quality GPSr.
The iPhone's Whereigo app which is free is GREAT too. I think it runs Whereigo cartridges even better than the Garmin hand helds like the Oregon and Colorado and Dakotas. Their players seem to crash a lot but the iPhone if it actually does crash, automatically saves and when you restart the app it brings you back to where you left off. Plus you can multitask with other apps at the same time like text or take a call or use the camera. The screen is great for Whereigos, nice and big and it allows sounds to be played if they are in the Cartridge.
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