Since having my life greatly altered with an iPhone 18 months ago, I have come to appreciate the impact certain apps have had in my daily life. A few noteworthy ones:
DAY ONE: This is a journaling app that allows you to make entries that get backed up to DropBox, include photos, automatically notes the weather, location, etc. As one of my life goals is to keep a daily journal for 5 years, this one has proved invaluable because it is so fun to use and review with photos. I make a point of taking a unique photo each day to keep it fresh and so far I have journaled for 161 straight days. I love that I can publish the entire thing as a PDF in the end too. It's existence is also the main reason I have neglected my blog the last 6 months.
FOG OF WORLD: This is madness for a map fan like me. I love turning on the app when I travel new places to clear the fog from the map.
THIS AMERICAN LIFE: I got hooked on this NPR program this past spring and so the app has been a mainstay on morning and afternoon commutes (and long distance drives with the family). Since the only way to listen to archives is online through a flash based program, I had to buy the $2 app and it's worth it being able to access the 500 episodes. I'm working my way back, so I'm on episode 438 (2011).
GUITUNE: $1. Cheapest and most convenient guitar tuner I have ever bought.
BEER BUDDY: A perfect way to track the brews you've tasted. It can scan beer barcodes, access the ratebeer.com database for ratings and reviews, allows you to add your own ratings, etc.