For me, a to-do list isn't much good if I can only use it on my Mac and not on my iPhone or iPad. Which is why I've been using the iOS app Listacular (free, $3 in-app purchase): It's an iOS list app that happens to be compatible with the TaskPaper format. I just point it at my TaskPaper to-do file (stored on Dropbox), and Listacular lets me see all of my to-do items, neatly formatted, with checkboxes and tags intact. Of course, the app can do more than just open and manage TaskPaper lists: It's also a general-purpose note-taker, outliner, and list manager. So even if you don't use TaskPaper, it's worth a look.
Dan Moren: Rowmote Pro
While I have a Harmony remote set up to control my Mac mini media center, I run into problems with it sometimes, which is why I turn to Rowmote Pro ($5). There are plenty of apps that let you control your Mac, but this universal offering from Evan Schoenberg is easy to use and has all the features I need.
Not only does it let me control my Mac using an Apple Remote-style interface, but it also features a real multitouch trackpad, a gesture-based mode, and a full keyboard. In addition, it's heavily configurable for almost all the Mac applications you might want to control. It's been on my iPhone's primary homescreen since day one, and if you have a Mac media center, I suggest you look into it, too.
Jason Snell: Pedometer++
I've always thought it was silly to wear a pedometer when the iPhone in my pocket contained its own accelerometer. But until the advent of the M7 coprocessor in the iPhone 5s, it was impractical for the device to constantly monitor the accelerometer — at least, not without running out of battery in far too short a time.
Now that I've got an iPhone 5s, I've got a pedometer that I carry in my pocket wherever I go. And with David Smith's excellent Pedometer++ (free), I've got a simple, effective log of all the steps I take every day with my iPhone.
Pedometer++ lets you set a daily step goal and displays the number of steps you take every day in a colorful bar chart. It's simple, attractive, and sure beats clipping a plastic pedometer to my belt.
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