Phone/tablet apps you use

The board feet question got me wondering, are there apps you use on your phone or tablet?

I picked up my first "smart" phone, which is a inexpensive, prepaid model that will expire in less then a month on time. I only bought it due to one app that was only available for smartphone or tablet, not pc as the phone was less then the cheapest tablet I could find.
Hoping I will still be able to use it on my wireless once the phone time expires, as I still use a candy bar style phone (week on a charge, less then $100 a year), but in case I can't.....

Are there any apps (particularly woodworking) that you use on your phone?

TIA

I have several calculators and the apps from the home improvement stores (helpful for checking actual store inventory, store location and item location within the store, and price). However, the one I turn to most often is a free app from Dewalt. It has a slew of free calculators (standard calc, area, length and volume conversion, slab, paint, drywall, studs - all free and come with the app. There is a board foot calculator hidden in the volume conversion calc along with things like bushels, dry gallons and barrels of oil. There are many many more available for a price and downloadable books on all sorts of construction, codes, etc.

You didn't mention if it was andriod, iphone, windows, other, but on Android the one I use most often is called Inches & Feet, which does fractional calculations. I have a bunch of the usb connected endoscopes that I use for inspections and the MScope app comes in handy for use with them. There is the Bubble App for using the phone as a level.

I use dropbox which has the option to automatically upload photos to my dropbox account and they sync over to my pc automatically. The use Tapatalk for browsing the forum and a few others.

Apps I used to use, like flash light, have become standard in the OS anymore, so don't have as many as I used to. I'm also pretty picky about installing apps that ask for permissions that just don't match the functionality of the app (i.e. a bubble level app that wants my contact list).

About the only one i use related to woodworking is tapatalk. Like Darren i am extremely picky about apps that want access to things that have nothing to do with the app.

I've used "Unit Converter" for years on both iPhone and Android phones. I was asked to teach a class on woodworking math a few months ago at the local woodworking club. I found a great app called "Handyman Calculator". It will calculate just about anything you might need (and several things you'll never need): construction, concrete, electricity, laminates, flooring, roofs, golden ratio, board feet and dozens more. I'm using it on an Android phone. If what you need to calculate isn't on the list, you probably don't need to calculate it anyway.