Here’s a quick list of the iPad/iPhone apps I use the most:

Goodreader

This app can read pretty much any file format but is best for reading PDFs. It can also play MP3s and movie files in a pinch. You can transfer files into and out of the app a variety of ways including DropBox, Mail (IMAP/POP3), Windows SMB, etc. The best file reader out there.

iAnnotate PDF

Another PDF reader that I use just for voice acting copy if I’m lucky enough to get it electronically. It has a ton of annotating features so you can mark up the copy with producer feedback. You can set pen width, colour, and all sorts of other things. Great software recommended to me by fellow voice actor, Richard Baldwin.

Casts

Software you can use to subscribe and listen to podcasts. By the far the best one I’ve tried. You can search, add your favourite ones, and it will download new episodes automatically. You can set when to delete an episode, etc, too. Subscriptions and “read” podcasts can be sync’d across devices via their optional free cloud service. Registration for this is a very simple, one step process. It’s a must for any podcast listener.

AppsGonefree

Multiple apps for free everyday. What more needs to be said?

xkcd

A free comic everyday. Quirky STEM (Science, Technology, Engineering, Math) based, geek humour.

Day One

A ton of experts recommend keeping a daily journal. This is the most popular app for this. It’s available for Mac OSX and iOS. You can set your entries to sync to Apple’s iCloud service for writing anywhere, anytime. Recommended by Michael Hyatt and many others.

Instapaper

This is a web clipping app. Register for an account and it will sync your clips across devices. What’s “web clipping?” At it’s most basic, this app allows you to save the text only portion of a website link for offline reading. Copy a website link to the clipboard, open the app and it will prompt you to save the page. You can tweak the font type and size or turn on an automatic “night mode” that will slowly dim the background based on the time of day. It’s sad that not all sites support it though.