In no particular order here is some I have installed on device. Not used them all but could be useful...
Emergency Button: Define a phone number and/or an email address and whenever you press the big red button, the distress signal will be sent out to these recipients along with your GPS/Network location (a google maps link) and a personalized message.
MapsWithMe Pro, Offline Maps:
The fastest offline maps of the entire world. Feel confident while traveling. Maps work everywhere, anytime!
BackCountry Navigator PRO GPS:
Use your phone or tablet as an offroad topo mapping GPS with the bestselling outdoor navigation app for Android! Explore beyond cell coverage for hiking, and trekking.
First Aid:
When you are in a emergency situation, how to deal with it? You need some instructions and First aid is your first choice.
(Note: Important to already have first aid skills but just in case use this as fall back/reference etc)
Fungitron - mushroom guide:
HIGHEST number of FREE mushrooms (70), with own, expert verified HQ photos. HIGHEST number of combinable identification parameters (~150).
Geocaching:
Use the Official Geocaching.com App to find cleverly hidden containers. The app unlocks the exclusive coordinates and info for nearly 2 million hidden geocaches.
Knots 3D:
Knots 3D - Tie, untie and rotate 85+ knots with your finger in 3D! ★
Our top-rated 3D knot app, will give you a whole new perspective on knots! Grab a piece of rope and have fun!
Mushrooms PRO:
+ + + The ultimate pocket sized identification tool for mushrooms! + + +
+++ 300 species - 2000 images - identification function - quiz +++
Mushtool - Mushroom:
Mushtool is an application for all the mushroom finders, from amateurs to professionals.
My Tracks:
My Tracks records your path, speed, distance, and elevation while you walk, run, bike, or do anything else outdoors. While recording, you can view your data live, annotate your path, and hear periodic voice announcements of your progress.
- Identify the mushroom with a great quality pictures.
ViewRanger Outdoors GPS & Maps:
Free Global Open Sourced Maps
ViewRanger is the complete offline mapping, navigation & guided trail service for Outdoor Enthusiasts. Perfect for backcountry exploring or simply days out in the frontcountry.
Wild Edibles:
Wild Edibles provides an intuitive and easy to use interface for identifying and using wild edible plants, drawing on the outstanding publications and extensive knowledge of "Wildman" Steve Brill.
SAS Survival Guide:
For over twenty years, the SAS Survival Guide has been the definitive guide to surviving any situation, anywhere in the world. Now, for the first time ever, the million-copy bestselling book and the hugely successful iPhone/iPad app, has been reinvented for the Android.
TVCatchup
Watch live TV with the convenience of an app.
FilmOn
Watch local and international TV stations.
Google Camera
Gives you ability to use Photo Sphere, which basically means you can do full spherical 360 photos like street view
(You need Android 4.4 and above though)