As I wrote the first draft of this post, I quickly realized that this post is actually about far more than just iOS apps. It's about taking advantage of computers to their fullest extent, particularly around automating one's life on the go. Enjoy.
Chrome - Chrome works beautifully across all major computing platforms. Everything that can sync, does sync, seamlessly.
Clear - The simplest, best to-do list app on the market. And it syncs with the Mac desktop client via iCloud, making it even better. Clear literally drives my day. Using Clear, I manage my personal and work to do lists, books to read, songs to download, and even to help grow my vocabulary.
DI Radio - The ultimate electronic music app. It has an amazing selection of electronic music, and live streams from some of the biggest electronic music festivals in the country.
Evernote - There's good reasons why this is one of the most popular apps on the entire App Store. It's note taking done right across all major computing platforms. I also use Evernote Hello and Evernote Food; they're pretty good too.
FitBit - I have the FitBit Aria wireless scale. It's awesome. It syncs to my phone and graphs key metrics in seconds. And soon, it will also sync from the upcoming FitBit Flex. I'm excited to be part of the burgeoning quantified self movement.
Google - Google's general app is actually more useful than Chrome because it loads faster, and offers Google Now.
Gym Buddy - sadly, the developer no longer updates the app (though there are rumors that he's started working on it again). Gym Buddy is the best workout tracker and manager on the market. I've tried over a dozen of them, and this one is hands down the easiest and fastest to use. Speed is paramount because I only have 60 seconds between sets, and Gym Buddy understands that. I don't want to spend 60 seconds playing with my phone between sets. I want to spend no more than 5, and Gym Buddy empowers me to do just that.
Kayak Pro - I travel a lot for work. Kayak automates every step. They offer a great search tool (though Hipmunk's search interface is better). But even if I don't buy from Kayak, I forward every itinerary to Kayak anyways. 24 hours before my flight, Kayak reminds me to check in to get a good seat. When I get to the airport, Kayak presents all of the key information I need to navigate the airport, integrates with Passbook, and of course even stores an electronic version of my boarding pass. Awesome.
Kindle - I read a lot. Especially when traveling. The Kindle platform is the best ebook platform that spans all major computing platforms, period.
Mailbox - Mailbox deserves all of its hype and praise (though not a $100M valuation; that's just absurd). Mailbox is the best email client on the market. Mailbox powers my Gmail to stay at inbox zero all day everyday. My Exchange account at work is a totally different story.
Mint.com - I can track all of my personal financial information across all financial institutions, and measure spending against predefined budgets and goals in one tap from the home screen. I love it.
Podcasts (by Apple) - Although the first few iterations of this app were pretty bad, Podcasts is now a very functional app that allows me to take the always incredible Critical Path with me everywhere I go.
Reeder - An amazing Google Reader client with a beautiful and speed focused design. Reeder powers me to read through 350 headlines during most weekdays, and 150 daily during the weekends. Of those, I actually read between 5-10% of the total volume most days. Reeder has nailed the high-volume reading process to a tee.
Siri - Although it's not a 3rd party app, Siri is pretty amazing. 90% of my Siri use occurs while driving. The last 10% while I'm in bed and too tired to actually use my phone. While practically dead in my bed, I can, without any dexterity or eloquence, moan "Set an alarm for 7AM" and Siri will take care of the rest. Thanks, Siri. Plus, I trained Siri to call me "Big Daddy". There's no way that an app that calls me Big Daddy can't make it into my favorites list.
Sleep Cycle - It figures out the best time to wake me up within a given 30 minute window based on where I am in my sleep cycle. It calculates sleep cycles based on body movements (the phone needs to rest on the bed while you're sleeping). During the heaviest phases of sleep, I move very little, and in the lighter phases, I move more. It detects that based on the iPhone's accelerometer, and wakes me up accordingly. Genius.
Songza - This is what Pandora wishes it was. It offers better, contextual categories than Pandora, and ad-free listening.
Spotify - This is what iTunes wishes it was. For the first time ever, I'm paying for music. That tells you something.
Sunrise - Sunrise is without a doubt the best calendar if you live in Gmail / Google Apps. The interface is clean and the scrolling list is awesome. It automatically links to phone numbers and addresses, pulls in contact details from LinkedIn and associated emails and documents too. The developers realized that a digital calendar shouldn't just be a calendar, but should intelligently present the information you need to know when you need to know it. Genius.
Today Weather - The best weather app on iOS. See the picture below. Each square represents a full screen view. Just swipe between screens. The left-most column offers a gorgeous graphical 7 day forecast, and the right-most column offers an hour-by-hour guide. The middle column provides 1 click access to a radar map. It provides everything I need to know in a highly intuitive and polished packaged.
Way of Life - I use this to stay healthy and build positive new habbits. I've tried at least a half-a-dozen competitive apps. Way of Life provides the best overall flexibility and usability. It's easily worth the $5 that the developer asks for.