Oh how I love my iPad. I say that it is my second brain. Here are a few of the apps that I use regularly.
Daily Notes + ToDo
This is one of my very favorite apps. It functions like a DayBook. I use it as a journal when I go to sit before the Blessed Sacrament. I use it as a place to keep track of phone numbers and passwords and students and other assorted tidbits of information at work. It is password protected, so that even if someone is using your device they can't stumble upon whatever information you may have stashed there. You can add photographs to an entry, which would be really handy with the iPad2 or with an iPhone. I can take notes here - say at a faculty meeting - and then immediately email them to whoever might need them. About the only thing that I routinely wish that it had was a way to emphasize text - with Bold or Italics. I bought this app - I think it was $3 or $4. Worth it! There is also a "To Do" list feature, but I have used that rarely.
I believe this was a free app, but so well done and useful. If it wasn't for the shock factor of the little old ladies at my parish, and the fact that I sometimes like to take notes on the homily (just a word or phrase or two) I might give up my paper missal and just use this to follow the Mass readings for daily Mass. The Breviary has all of what you need to pray Morning Prayer, Evening Prayer, Night Prayer and the Office of Readings. I think it also has some of the Midday Psalms.
Do you love sticky notes? Well....there's an app for that!! I use mine as reminders for things that need to be done. And when it is completed, I drag it over to the pile on the right. A sense of accomplishment! There is a free version, but you are limited to 25 notes. I think this version was $1.99 or so. It's an organizational help for when I am feeling overwhelmed or just lost.
And a Bonus App that you should check out is the Merriam Webster Dictionary. You can speak a word into your device and it will tell you how to spell the word. That was a free one...and very cool. I don't use it very often, but it's useful for impressing non-technical people. :-)