For $.99 you can turn your iPhone or iPad into a GPS that can work offline. You can save tracks, embed pictures in map, and share your location with others.
National Geographic World Atlas
Get detailed maps of the entire world with the same detail as a National Geographic map. Download this application for $1.99.
Peterson Feeder Birds of North America
Peterson Field Guides have been around for a long time and are well regarded by the birding community. Make quick and accurate identification of over 160 backyard bird species with this free application.
Sygic GPS Navigation
Access TomTom maps offline with this free Android app. You do not even need to be connected to the Internet to use it.
Trimble Outdoors Navigator
Use this app for on-trail or off-trail hiking. Download a topographical map before a hike and see where you are even when you can’t get cell reception. This app uses your GPS function to put your current position directly on the map. It’s free.
Yahoo Weather App
This app is highly rated and it's free. It offers notifications, interactive features and animations.