The app I use most on my iPhone is without a doubt Instapaper. I use it to catalog my web browsing. And I love how it syncs to readable form on all my devices. It makes reading enjoyable because it’s seamless and convenient.

But what I love most is how thoughtfully designed it is. What do I mean by this? Let me illustrate with examples.

When browsing the web on the phone I occasionally copy the URL to the clipboard to read later. Sometimes I need to do this when I want to import into Instapaper’s Read Later functionality. So I was delighted when all I had to do was launch Instapaper and it took care of the rest:

When you read an article in Instapaper you can go back to your list by tapping the article and having the Back button appear at bottom. One day while reading the end of an article I was preparing myself mentally to tap the screen to navigate back to the list. It looked something like this:

To my delight, however, I didn’t need to tap because as I approached the bottom, I got this:

The bottom navigation bar with the Back button automatically slid into view (left-most icon). Awesome! No need to tap because the application proactively predicted my next action.

This is delightful design. It’s delightful because I didn’t expect it, and when it did happen, I was grateful it did.

At its core delightful design is about caring. It’s about empathy. (Which, when you think about it, is what design really is.) Someone at Instapaper cared enough to put themselves in the user’s shoes to imagine the question: What can we do here to help the customer?

Great design like this builds relationships with your customers by showing that someone cared enough to understand you. That’s a great thing. No one likes to be ignored. It’s always a good feeling knowing someone put the effort into thinking things through to make the experience better.

As a result, I’ve decided to subscribe $1/month to Instapaper’s development. Money well spent.