Ask HN: What Mobile Apps do You Frequently Use, Why?

It'd be really interesting to know which apps the HN community have/ use frequently on their phones. I'll give it a go first: - Fantastical: Calendar on steroids - Evernote: Note taking - Dropbox: Easy access to all my files - Kindle: Read books while commuting - Reeder: Stay up to date with my RSS feed - Trello: Used to manage my todos (I have the following board: doing, to do, goal, done, icebox) - Clear: Awesome todo list I use for things that don't belong in Trello, such as groceries - MapMyRun: Track distance/ time for when I go jogging - Skype: Chat with the family that lives abroad - i-Qi timer: Time I use to wake me up from Meditation - Daily Goals: Track and measure small daily goals (read, call a friend, stretch, floss, etc) - Spotify: Music on the go - Audience: Awesome Google Analytics app - AdSenseHQ: Keep track of my Google Adsense Revenue - Embark NYC: NYC Transit app - Groupon: I only use it for a daily deal this great nearby indian restaurant has :) - Dictionary: Comes in more handy that I'd like to admit - Google Maps: The name says it all - 500px: Used whenever I need to see something visually appealing or need some inspiration