Why does NRS only write apps for Android?
NASA Rally Sport has ten Android apps in the Google Play store. These target various rally related functions, but mostly deal with rally timing and rally communication. Often when a new app is announced, or an upgrade is announced, someone will ask "Is there an Apple/iOS version?" and the answer is no. Here are the reasons why we only do Android.
Primary Task
The most important app we have, with the largest global user base, is the Rally Checkpoint Clock. This is the app used by the volunteers and officials to record racer times all over the course. This app in installed on Barnes and Noble Nook eReaders. These devices are Android, and there is no equivalent Apple/iOS device. There just isn't a 6" Apple/iOS tablet that can be purchased for under $50, which also can be viewed in full sunlight like an e-Ink screen, and which has a battery that lasts all weekend. So NRS develops primarily for Android because the most important app we make can only run on Android-only hardware.
Market Size
If one wanted to build a non-free app, to sell for profit, building an Apple/iOS app is a good way to go, in America. There's a sizable market for these expensive phones in the US and the amount of money spent buying apps in the US on Apple/iOS is large. However, that reasoning doesn't hold up when one's intent is to give away free software. In the US, 44% of phones are Apple/iOS, and 52% are Android. Globally though, Apple/iOS is only 12% and Android is 87%. The worldwide market for this technology is overwhelmingly Android. And NASA Rally Sport is already working with users on multiple other continents helping them with their rally scoring efforts. The Rally Checkpoint Clock is used all over the world, here is a map of usage during 2016:
Cost
To publish apps in the Android store, there's a one time fee of $25. To publish apps in the Apple store is $99 per year, and if you stop paying, your apps are removed from the Apple store. At NRS we've been around for nearly 15 years already and we approach these things with a 10-year view. "Do we want to spend $1,000 over the next decade to have an app listed in the Apple store that we can't use on any of our timing hardware? What does this get us?" Add to that the Apple computers needed to develop the app, and that's several thousands dollars more. The Android tools, in comparison, are free and can run on Windows, Linux, or iOS machines.
All of this assume that the software engineering costs are zero. It's quite common when one hires a company for development that you would pay $100 to $150 per hour for development costs. Fifty hours here, fifty hours there... now you're talking real money.
Resources
There's only so much time in the day. All of the software at NRS is written in-house by one person. At any one time there are many "make rally awesome" projects on the back burner, and to have to do them all twice is a lot off effort. We could outsource these projects, but custom software is very expensive. Industry averages peg the development cost for these sorts of things as between $25,000 and $50,000 per app. NRS doesn't want to raise rally license cost to cover porting software.
The time span for the projects is also very long: The NRS scoring software has been under continual development for six years. Likewise, the Android Rally Checkpoint Clock has been under development for the last three years. So the it's not possible to "port it to Apple" and then walk away... the result of that would be outdated in a couple months. The full NRS software ecosystem, which is a combination of user accounts, back end servers, Android apps, is well over 100,000 lines of custom code. It is continually evolving at rapid pace.
Basically all this comes down to "we build all the awesome software we can to move the sport forward, but the return on investment (measured in time and dollars) isn't there to justify building it twice".