Brett Terpstra (twitter) is my kind of nerd. He is an ingenious programmer that makes useful stuff all day (like nvALT and InstapaperBeyond). In my mind, Brett is like some benevolent mad scientist who takes things I love (like TextExpander and Notational Velocity) and starts bolting on exgra limbs. Most recently Brett made a Web site, markdownrules, that looks at a URL and spits back a markdown file. I had the pleasure of making friends with Brett at Macworld this year and am happy to report that, in addition to his coding prowess, Brett is a stand up guy. If you haven’t already, keep an eye on Brett because you just never know what he’ll do next.

So Brett, show us your homescreen.

What are your most interesting home screen apps?

DuckDuckGo, the official app for the DuckDuckGo search engine, which is also brilliant, but I won’t go into that
1Password is essential to me (full disclosure: I work for Agile Web Solutions)
PlaySafe is the simplest, best-looking touch controller for music, and I use it every time I’m in my car
Camera Plus Pro is pretty spectacular so far. I just discovered it at Macworld this year, and I’m still breaking it in.

The apps on my iPhone’s home screen are, by and large, not my most exciting apps. They’re mostly workhorses. I’m going to stick with my iPhone for this chat, but I should mention that I’ve found that my iPhone and my iPad have very different apps on their home screen. Each device is better suited to certain environments and types of apps (I actually have games on the home screen of my iPad).

What gets an app onto your iPhone home screen?

It’s a pretty simple system. Apps on the home screen are ones that are either frequently used, or ones that I want fast access to. Shazam is an example of the latter. I don’t use it that often, but when I need it I usually don’t have time for a lot of tapping around. This is doubly true of the Dock, where QuickCal, Flashlight and Camera Plus Pro live. All three are useless if I miss an opportunity (or run into a door) while fumbling for them.

What is your favorite app?

It seems to change at least monthly. I’m fickle. Right now, I’m really loving Trunk Notes and Nebulous Notes (on both iPhone and iPad). Trunk Notes because it gives me a wiki that I can edit, search and browse on my iPhone, iPad and through any web browser, and because it syncs to Dropbox where I can edit in TextMate (and navigate using the Plain Text Wiki bundle), preview in Quick Look and search with Spotlight. Interoperability with my OS X workflow remains a major factor for me, though I’d love to someday be computing entirely on a more mobile platform. Anyway, Trunk Notes is also Markdown-based, and nothing in my geek world really makes me happier than Markdown.

Markdown is also the reason I like Nebulous. It doesn’t bill itself as a Markdown editor, but its ability to run user-defined Macros (including wrapping selected text) is perfect for that. Selecting text and pressing a button to have it wrapped in square brackets followed by a pair of parenthesis? Priceless.

Which app is your guilty pleasure?

Infinity Blade.

What is the app you are still missing?

I’m an obsessive collector of note-taking apps. To a fault. I’m still looking for the perfect capture tool that has it all in one, but I don’t really know what that would look like, or if I’d like it when I saw it. I like mind mapping, I like using text recognition in photos, and I love plain text notes. Honestly, though, I don’t think I’d love an app that did all of that at once. I just don’t see how it could be good at any of them if it tried to do all of them.

Answering this question actually makes me realize I have everything I want right now, albeit in separate apps. Good deal, though, I get to be surprised when some new and indispensable app drops into my life.

How many times a day do you use your iPhone?

It depends on the day. I use it every day, but some days it’s an alarm clock and an MP3 player (and a flashlight if I go to bed later than my wife). Some days it’s my GPS system, my note and task capture tool, my news, my leisure, my expense and time tracker and my connection to other people. On those days, I probably pull it out of my pocket a hundred times. But who’s counting?

Well, I guess my wife is, at least when we’re eating out with friends.

What is your favorite feature of the iPhone?

I think the feature that fascinates me the most is motion sensitivity with the accelerometer and gyroscope. It’s more because of the possibilities than because of any current implementation. It’s added an aspect to everyday app development that’s beginning to change the language of interface design. A few apps have made great use of it, even with the simplest of gestures (I fondly recall the first time I used it in Instapaper). Some apps make a mockery of it, but I think we’ll see more innovative (and appropriate) uses as time goes on. Can we quit with the shake-to-undo thing, though? It’s pretty asinine, even when it works properly.

Anything else you’d like to share?

You ask a dangerous question, my friend. I could probably talk an hour each about every app on my iPhone. For everybody’s sake, I’ll stop there.

Thanks Brett!