On the iOS side of things I have a few apps on my iphone:
- Expositor Lite - which is just a digital version of the classic paper slide-rule style of exposure calculator. I mainly have this on as I am trying to remember a few more exposure settings for common lighting environments other than Sunny 16
- Pocket Light Meter - I really do not use it a lot but it is nice to have a spare light meter around if I need a backup. This is free but I use it enuff that I clicked on the 'by the developer a pint' button
i was going to buy the massive dev app but, frankly, at $8.99 it is a bit much for me. The $5 I voluntarily paid for the light meter app is about as much as I want to spend on an app that replicates the info that I can easily find on the web.
Speaking of which, I have started saving PDFs on my iphone (on the iphone I do that by saving them to ibooks) and you can obviously do the same with other devices. I am mainly using HC-110 right now so I have
http://www.photostock.fr/site/FICHE_TECHNIQUE/HC110.pdf saved there and a couple of manuals (courtesy of butkus) for the sekonic meter (I am playing with for the first time in years) and for a couple of cameras which I need the info for. I also keep crib notes for random bits of info, and I turn to them as often as the apps. For example, what the zone focusing distances are for the various symbols on the different cameras I have. Another example is I am trying to remember a few more rules other than Sunny 16, so I have taken all the situations that paper exposure calculators have and distilled that down to a half a dozen environments
I commonly shoot in and have saved that as a note
My daughter is into a lot of photomanipulation these days and she has filterstorm and snapspeed on her ipad. They are good but not for me at this point in my life -- I have generally moved past my 'photoshopping' point in life and when I am not working I am preferring to only using Pshop for adjusting tonal values, cropping, and dust zapping -- so i really do not want to use these features on a tablet or phone. As my daughter pointed out, I mainly use the camera on my phone for taking pictures of my old cameras, haha.