In the latest field inquiry course which I attended, I downloaded the clinometer, stop watch and smart compass to my handphone and tablet. By using the clinometer, we could actually measure the gradient of the beach easily. At every 1m interval, we measured the gradient by placing the phone/tablet on the beach and recorded the gradient. We were able to plot the beach profile from all the data collected. We realised that the gradient was steeper on one side of the beach behind the breakwater and suspected there is a drift of sediments towards the east - we had used compass application to determine our location.
I realised that if we want to use the ranging poles and clinometer to measure angle - the smart protractor would be useful as well.
We also decided to check on the wave energy and determine whether the wave energy is high and the need to construct the breakwater to reduce the energy before it hits the coast. Using the stopwatch and timer we time the no. of waves per min. True enough the count was 20 per min which indicated high wave energy. Another useful application would be the smart measure which we could measure the height of the breakwaters or the distance between them. It seemed that the breakwaters over our stretch of coast are slightly higher and nearer to each other.
Sketching for geographical inquiry - you can use the app Sketchart or protrait sketch to turn your image into a sketch instantly!
Sketch guru is also very useful in creating a field sketch instantly. 
Of course, many people would have found Google Map useful. Whenever I am at a new place, I will use it to help me to navigate around. You must also install Street View on Google Map. With Google Maps Street View, you can explore the world at street level. Just open Google Maps, search for a place or long-press the map, and tap the Street View option.
You can measure the area and distance on Google Map using Area Calculator which is relatively easy to use as shown below:
Use Google Earth to fly around the planet with the swipe of a finger. Search by voice for cities, places, and businesses. Browse layers including roads, borders, places, photos and more. For tablet users (Android 3.0 or newer), you can get easy access to search, reset-to-north, my location, and layers. Also, on tablets and select phones, you can now explore the same photo-realistic 3D buildings that have previously only been accessible with the desktop version of Google Earth.
I also like Earth Zoom Pro - you can zoom from Space to Ground level to famous places such as Machu Picchu, Petra, The Forbidden City, Pyramids, Taj Mahal More
Google Goggles is another useful application which could help me to identify an object.
The following are some useful apps on weather studies -
The weather channel allows one to track the weather conditions and forecast around the world and you can choose the layer as well as the type of map. There are also videos related to videos as well.
Weatherlah keeps all Singaporeans up to date about the latest weather forecast with a clean and easy to use interface. The app can notify you of incoming rain, rise in PSI levels and even extreme weather warnings.You can also click on drain in the map mode to see whether the drains are flooded or low in water level around Singapore.
Wind speed is a wind convertor which allows you to convert between many various wind speed measurement scales e.g. Beaufort scales to km per hour .Click on the i icon and you can find out more what the scale represent e.g. on Beaufort scale 5 leaves begin to sway and on beaufort scale 10 trees are broken off or uprooted.
T-counter is very useful in counting traffic - you can have 4 counters at the same time e.g. one for car, one for bus, one for taxi and one for others! just touch the + button to add on. Good for field inquiry in Human Geography for human traffic as well.
Another tool useful for human geog is tape-a-talk which is useful for interviews. The recording is saved in wav file and can be played back on computers. Of course you could also use the camera function on your phone but some people might not want to be captured on video.
You can create a dropbox account on your computer as well as download the dropbox app onto your handphone and the files can all be uploaded and share.
I also like Kingoffice which allows you to view as well as edit office documents - words, excel, powerpoint.
Another amazing application is 3D Earthquake. Like what I have told my students - earthquakes occur everyday - just that the magnitude might be small and not reported in the news. It shows the plate tectonic - that the plates are moving and you can change the setting to show the plate boundaries and how these earthquakes coincides with the plate boundaries.
Simearthquake is another app which is very good to illustrate how magnitude affects the extent of damage from earthquake.
Volcano report is also an interesting app to know the latest volcanic eruptions in the world. Explore volcanoes which have been active in the last week on an interactive map. For every single volcano you get detailed information about the ongoing activity and their eruptions.
Of course as a geography teacher, the app World Map and National Geographic Explorer are also indispensable. However I could not add National Geographic Explorer to my Motorola Xoom - only on my husband's Lenovo K1
Learn more about Geography Natural and Man-made Features - Natural features part 1 and part 2, Man-made features part 1 and part 2. There are also many other apps on Geography games and quiz. And of course the best part about all these apps are that they are free!
A similar sharing by another teacher in UK but more of iphone in Geography fieldwork -https://docs.google.com/present/view?id=dhntzwtf_58cpcsgjg8
