The Wall Street Journal has run a series of articles about the app economy this week, identifying the app ecosystem as a $25 billion business. They write:

The apps industry "is like cars at the turn of the last century," said Simon Khalaf, chief executive of mobile analytics firm Flurry Inc. "You see the growth of roads and know they're going to be big. But it is still early days."

If you're interested in mobile, and apps in particular, I highly recommend searching this series of articles out.

When my co-founders and I started PointAbout, a mobile app dev shop in 2008, we had a really hard time convincing businesses that apps were more than just a fad. Then in the 4th quarter of 2009 something significant happened: I started to see budgets for app creation move from the "experimental" bucket to a dedicated budget. That's when the most forward-thinking businesses started to build mobile apps and we were able to build a strong business making apps for Disney, The Washington Post, Cars.com and many others.

But still, many businesses don't get it. I recently wrote a warning to Fortune 1000 CEOs because I'm convinced many of them will be fired for underestimating the impact of mobile on their businesses.

For businesses that are trying to figure out how to really double down on mobile, I'd like to highlight a startup that recently launched called Automatic. It combines a $70 accessory that plugs into a car's ODBII port with a mobile app, allowing the car to communicate with the phone. This is a beautiful example of how a company took something that's always been available -- diagnostic information from your car -- and turned it into something humans actually care about, with features like "Never forget where you parked," "Automatic calls for help in a crash," "Save hundreds on gas every year" and "Keep your engine healthy." The way Automatic is unleashing data that's always been available in a new and very innovative (and valuable) way via the mobile device is a great example of how mobile is changing everything.

I'd also like to take a quick moment to highlight native apps vs. mobile web. I've written extensively on this topic before, but I just found that Basecamp has released a native mobile app. This was surprising to me since Basecamp used to have a native app, then removed in 2011 to focus on a responsive HTML5 web strategy, but is now back to a native mobile app. I don't know what the motivations of 37 Signals were to return to native, but it's a trend I've seen happen several times, including at Facebook, where Mashable writes:

But the benefits of cross-platform development weren't enough to outweigh the downsides of HTML5, which pulls in data much more slowly than native code, and is much less stable.
"It turns out, 'good enough' wasn't good enough," Zuckerberg said of the company's HTML5-based mobile apps.

Needless to say, I'm a big believer in the app economy, and even though there are still those who preach responsive HTML5 design for everything, when you look at the data, actual engagement on mobile from native apps far outstrips mobile web usage.

That's not to say that there's no place for mobile web, because there absolutely is, but if a business is serious about mobile it will likely have to start focusing on making native apps that add true value to its userbase.

So to help showcase the value of mobile, and apps in particular, I figured I'd write about some of the apps I rely on, and why. I'd also love to hear from you in the comments below about what apps you use and love on a regular basis. What I'm not interested in is apps that you've downloaded but never open (I wrote a blog about the coming engagement crush in mobile because that's going to be a big problem). Just tell me about the apps you use often.

Here are the apps I use and love on a regular basis (at least weekly, often daily):

Let me start with the apps that sit in the tray of my iPhone, meaning they're the most accessible:

Phone: This one's pretty self explanatory, although I don't make calls as much as I used to, as I prefer asynchronous communication like email, SMS and IM.

Gmail: I don't use the iPhone's native mail client. Instead I use Gmail's new & refreshed mail app, which is very good. I pursue an "Inbox Zero" philosophy, which is explained in point 5 on this efficiency blog, and the Gmail app is great for that.

Chrome: I also rarely use the iPhone's built in browser, Safari. Instead, I prefer Chrome because it lets me open unlimited tabs and syncs open tabs across my laptop, iPad and iPhone.

Socialcam: I've written an entire blog on why I love SocialCam, and I keep this app in my tray so it's readily accessible when I want to shoot a spur of the moment video.

Here are the apps on the first screen of my iPhone -- these are the apps I use the most:

Spotify: This app keeps me from having to think about music. It's cut deals with just about every record company out there, allowing me to find any music I want to listen to at any time. I can create playlists and download them for offline use. Spotify has a Pandora-like radio functionality that lets me listen to songs similar to the ones I know I like, which I use often. One of my favorite features is an automatically created playlist called "Liked from Radio" which has all the songs I've ever given a thumbs-up to while training a station.

Evernote: Evernote is a great "external brain" that works well for capturing notes and much more. It has fantastic OCR abilities to make text in pictures you take searchable. In fact, I'm writing this blog post in Evernote on my iPad, using a great keyboard that lets me type as quickly on the iPad as I can on a regular computer, while listening to Spotify in offline mode on a flight.

Pivotal Tracker: I use this app to organize and prioritize my life. While it's a bit clunky to learn, it works well once you've gotten the hang of it, and I understand that a product refresh is coming. Here's more on how I use Pivotal Tracker in general.

Podcasts: I like to listen to RadioLab, Marketplace, 60 Minutes, Planet Money and This American Life with the podcast app, all at 2x speed. While some people gripe about this app, I find it elegant and useful.

Find My Friends: When I'm going out in a group, especially if it's an extended event like a conference, I find this app invaluable. It allows me to easily locate everyone in the group. I wish the app (or one like it) worked across devices, There's an app called Twist that's trying to solve this problem, but I find that the real-time map of everyone in my group is something that I like too much to give up, and I've only found it in FMF.

Twitter: I like having easy, instant access to Twitter on my home screen.

Talkatone: This app allows me to sign into my instant messaging accounts, including Gtalk and Facebook, so I can be connected from anywhere. It also has a solid VoIP phone that works well.

Reeder: This is an elegant RSS reader, and it allows me to stay up to date on my Google Reader feeds.

RunKeeper: Being able to track my runs with RunKeeper is my favorite part of running, and it gets me out on runs when I would otherwise stay home.

Reminders (OEM): My wife and I both use this app, enabling us to share reminder lists. It's an awesome feeling to arrive at Costco, split up, and watch each other check items off the Costco list as we pick up what we need. It makes shopping a comparative breeze. One usability issue: You can't share reminder lists from the app; you have to do it on iCloud.com. An annoying stumble for an otherwise fantastic app.

Notes (OEM): With the newest Mac operating system this app syncs across all Apple devices, so you can write a note on your iPhone and then retrieve it on your Mac. It's a bit of an overlap with Evernote. I find that when i want to write something quick, I'll use Notes, and for something more in-depth I'll use Evernote. I may try to consolidate everything in Evernote now that they've refreshed their native Mac app.

GasBuddy: I drive a diesel truck, and with fuel over $4 gallon, I rely on this app to help me find the cheapest fuel around. It's a crowd-sourced app and is remarkably accurate. Gas prices can often fluctuate by over 20 cents/gallon within a half mile, so this app provides real savings.

USAA: My bank has an app that lets me easily transfer funds from this app, as well as deposit checks just by taking pictures of them. The check is then immediately credited to my account -- no waiting. Very handy.

There are other apps on my home screen that are useful but I don't have much to say about, including

Calendar, Messages, Apple Maps, Camera, Camera+, Clock, and Calculator.

Here are apps I use on a regular basis, but not often enough to justify being on my home screen:

WhiteNoise: A great app that helps me get to sleep when I'm in a noisy environment.

Lockitron: I can lock & unlock my door remotely with this app. I love not having to carry a key around.

1password: A great password app that syncs with the desktop.

SkiTracks: A very fun app that helps you measure your performance on the slopes. It's funny how the experience of skiing changes once you can measure it. Suddenly my friends and I were competing to see who could clock the fastest downhill speed.

Tapatalk: A forum app that allows for a more mobile-friendly experience. Many forums use this app, or one like it.

Pocket: When someone sends me an article to read, I usually immediately save it to Pocket on my desktop via a Chrome extension so it doesn't interrupt whatever I'm doing. I can then read the article with this app on my phone.

Find My iPhone: When I was on vacation in USVI, I realized I didn't have my phone on me. I was in a van traveling across to the other side of the island. I was able to use this app on my wife's iPhone to locate my phone, which I had left in a hotel lobby, remotely lock it, and display a message stating that I was coming back to retrieve it, along with a ping tone so it would be found by the hotel staff. From that moment on, I've been sold on the usefulness of this app. It's even great if you just can't find your phone in the house. You can send a ping tone to it to help you locate the phone.

That's my list. I'd love to know what apps you rely on in the comments below.