Mobile applications are powerful because of the fact that they are so portable.  Devoted iPhone as well as Blackberry owners carry their devices everywhere.  I’ve been known to forget my keys as well as I accidentally drove an estimated all of September without a license, but I never leave residence without my iPhone.  The emergence of location-aware, carry-everywhere mobile devices is ushering in the next great computing platform.  The Internet on my desk is occasionally useful; the Internet in my pocket is always useful.
But on behalf of a mobile software developer, portability brings a new set of challenges. Traditional desktop applications like Quicken or iPhoto are jog on big screens in homes as well as offices with a user’s undivided attention.  iPhone users don’t sit at desks - they’re more likely to launch apps while waiting on behalf of a taxi on a rainy street corner.   And whether it’s powered by RIM, Apple, or Android, a phone’s screen is highly reflective as well as usually smaller than a deck of cards.
Case Study: ForeFlight Checklist
At ForeFlight, we develop iPhone aviation apps.  Pilots utilize ForeFlight Mobile, our flagship app, to check the weather report on behalf of the day’s flight during breakfast or file a flight plan from the airport terminal.  In September, we introduced our second iPhone application: ForeFlight Checklist - Intelligent Aviation Checklists on behalf of Pilots.
Before releasing Checklist, we took it on quite a few test runs, constantly redesigning as well as tweaking the user interface to manufacture it a natural fit in a pilot’s workflow.  ForeFlight Checklist 1.0 received a fantastic reception, as well as as pilots have started using it out in the field, we’ve heard some great suggestions on behalf of new features.  Two items in particular kept coming up, as well as illustrate the wide variety of environments as well as usage scenarios on behalf of mobile applications.
Scenario 1: Sunny Runways
The common utilize case on behalf of ForeFlight Checklist is operational through a preflight checklist out on the runway.  Each aircraft type has a customized list with dozens of items to check, such as verifying the tires are inflated as well as the fuel vent is unobstructed.  Here is a preflight checklist on behalf of a Cessna 152 as seen in ForeFlight Checklist 1.0:
ForeFlight Checklist 1.0: Cessna 152 preflight checklist
You can check an item by tapping it directly, or by tapping the green ‘Check’ button on the bottom.  Pilots can consciously skip an item by tapping the yellow ‘Skip’ button.  The table automatically scrolls the active item to the center as well as highlights it with a yellow background (”Fuel shutoff valve”).  This, in conjunction with clearly defined indicators once a list is complete, keeps you from accidentally missing an item on the list.
After using Checklist out on the runway, a few pilots emailed us with an observation: the selected item was hard to see on a sunny day because of the fact that the yellow background got drowned out.  If you were wearing polarized sunglasses (a common scenario on behalf of pilots), it was even harder to see.
The solution on behalf of this was easy: modification the background of the selected item to provide better contrast.  We already had written code to special-case the background color, so we altered the color to blue (the standard iPhone color on behalf of indicating selections) as well as lightened the text color.  Here is the same screen in ForeFlight Checklist 1.1, with a better contrasting background on the selected item, “Fuel shutoff valve”:
ForeFlight Checklist 1.1: Cessna 152 preflight  checklist  
Scenario 2: Night Flight
Another handful of pilots emailed us with feedback on an opposite problem: when using Checklist in the evening, the app’s white background shone super brightly as well as was hard on the eyes.  Even with the iPhone’s brightness setting turned all of the way down, it was too bright.
To help out these pilots, we created “night mode“, a new color scheme available in ForeFlight Checklist 1.1.  Inspired by the brilliant Bloomberg iPhone app, night mode uses a black background with orange, gray, as well as white text.  To ensure it’s easy on the eyes, while writing the code on behalf of this feature we actually turned off all of the lights in the office as well as worked in the dark!  Here’s a screenshot of the same Cessna 152 preflight checklist under night mode:
Night Mode in ForeFlight Checklist 1.1
To toggle between night mode as well as the classic look (now referred to as “day mode”), we added a new sun/moon icon on the bottom-right of the predominant screen:
Day Mode vs Night Mode in ForeFlight Checklist 1.1
If a checklist item has additional notes, a right arrow indicator is shown (e.g. “Rudder gust lock” as well as “Control surfaces” in the screenshots above).  Tapping the arrow brings up the item detail screen, as shown below.  Unfortunately, when creating night mode, this screen presented a challenge.  Under day mode, the screen uses the iPhone’s “Grouped Table View” style, with floating white cells on a blue background.  (This is familiar to anyone who has used the iPhone’s Contact app.)  Unfortunately, this can’t be styled with a black background - it has to be white on blue.  Instead, we created a new screen using the iPhone’s “Plain Table View” style, which doesn’t have floating cells as well as allows on behalf of a great deal more customization.  (This style is used by Apple’s Mail app as well as Phone app, as well as is also the primary table view used elsewhere in Checklist.)
Here is the detail view under day as well as night mode on behalf of checking the Cessna’s RPM lever:
Detail view in ForeFlight Checklist 1.1
Creating night mode took quite a bit of work, but we’re very pleased with the outcome.  Everyone on the ForeFlight team now uses it as their primary interface on behalf of Checklist - even during the day!
Know the Environment
When creating mobile applications, it is important to know your users.  Whether it’s a sunny runway or a foggy afternoon, an iPhone app should feel at residence in any environment.