As principal of Micronautics Research I develop or oversee development of desktop and mobile client/server applications. We use whatever technology is appropriate for a client project.
I make a distinction between applications (apps) and web pages (HTML and HTML5). Over time this distinction will blur. This posting deals with current reality for apps that need to be developed and deployed using today’s technology.
Mobile and desktop apps can be described in terms of usability, performance, development cost, and maintainability; the latter is an indicator of the time, cost and risk of modifying an existing application. Whereas desktop environments are quite stable, new mobile devices and operating system versions now appear daily. Mobile apps are therefore have a much more difficult time staying relevant than do desktop apps. Mobile app environments also vary a lot more than desktop app environments.
There is no perfect one-size-fits-all technology for every app, and this is especially true for mobile apps. Some mobile apps must integrate tightly with the operating system; for mobile apps this currently means writing in Java for Android or Objective C for Apple iOS. The majority of mobile apps, however, must be deployed to any device that the user might happen to own; the time and cost required to target every possible device explodes unless a cross-platform technology is used.
I’d like to share a lesson learned from migrating several desktop apps to mobile apps. In order to reuse the original logic and data structures from the desktop app in various mobile apps, the logic and data structures must be cleanly separated from presentation to the greatest extent possible. We have yet to see a project where rework was not required in this regard before we could begin the task of making mobile versions.
Presentation logic for adaptable views is not much of an issue for desktop apps, but it is important when targeting devices whose resolutions and pixel densities vary greatly. Implementing the logic for adaptable views is not difficult, but designers today are generally unfamiliar with the issues of how to create adaptable designs for such a wide variety of platforms. We find that our interaction with designers has deepened when working on mobile projects.
Processing power varies greatly between mobile devices. Tablets have quite a bit more power than phones, and desktops have yet more power. However, mobile devices have specialized hardware not present in most desktops, such as GPS and various forms of telephony communications; many Android devices also have a built-in bar code scanner. When adapting a desktop app to run on mobile apps, we strongly suggest using built-in hardware to the greatest extent possible. Mobile apps should obtain data from hardware or remote services instead of asking the user to type, click or swipe.
We also enhance data structures as much as possible so less processing is required; although this is generally a good practice, today’s desktops are so powerful that careless programming often goes unnoticed. When an app is ported from a desktop environment to a mobile device, the reduced CPU and memory resources cause the app to run unacceptably slowly.
For applications that must continue to work on desktops after they are ported to mobile devices, we recommend identifying and optimizing the application core such that it is present without changes for all environments. Sometimes clients are surprised by the results of this partitioning process, because their assumptions of what is core do not align with actual commonalities between target environments.