Limits to growth

The shift from desktop and web applications to mobile applications entails many changes. There are changes in technology, new services and capabilities, and integration of apps and the sharing of data. Yet one change that has seen little discussion is the limits of an app's size.

Desktop applications could be as large as we wanted (and sometimes were larger than we wanted). It was easy to add a control to a dialog, or even to add a whole new dialog full of controls. A desktop application could start small and grow, and grow, and grow. After a short time, it was large. And after a little more time, it was "an unmanageable monstrosity".

The desktop PC technology supported this kind of growth. Desktop screens were large, and got larger over time. (Both in terms of absolute dimensions and pixel count.) The Windows UI philosophy allowed for (and encouraged) the use of dialogs to present information used less frequently that the information in the main window. Thus, application settings could be tucked away and kept out of sight, and users could go about their business without distractions.

But the world of mobile apps is different. I see three constraints on the size of apps.

First is the screen. Mobile apps must run on devices with smaller screens. Cell phones and tablets have screens that are smaller than desktop PC monitors, in both absolute dimensions and in pixel count. One cannot simply transfer a desktop UI to the mobile world; the screen is too small to display everything.

Second is the philosophy of app UI. Mobile apps show a few key pieces of information; desktop apps present dozens of fields and can use multiple dialogs to show more information. Dialogs and settings, encouraged in desktop applications, are discouraged in mobile apps. One cannot simply port a desktop application to the mobile world; the technique of hiding information is dialogs works poorly.

Third is the turnover in technology. Mobile apps are generally client-server apps with heavy processing on servers and minimal presentation on clients. The mobile app platforms change frequently, with new versions of cell phones and new types of devices (tablets and Windows 8 Metro devices). While there is some upward compatibility within product lines (apps from the iPhone will run on the iPad) there is a fair amount of work to make an app run on multiple platforms (such as porting an app from iPhone to Android or Windows 8). Desktop applications had a long, steady technology set for their UI; mobile apps have a technology set that changes quickly.

This third constraint interests me. The frequent changes in mobile devices and their operating systems means that app developers have incentive to update and revise their applications frequently. Certainly one can write an app for the earliest platforms such as iOS 1.0, but then you lose later functions. And the rise of competing platforms (Android, Windows 8) means new development efforts or you lose those shares of the market.

I expect that technology for mobile devices will continue to evolve at its rapid pace. (As some might say, this rapid pace is "the new normal" for mobile development.)

If mobile devices and operating systems continue to change, then apps will have to change with them. If the changes to devices and operating systems are large (say, voice recognition and gesture detection) then apps will need significant changes.

These kinds of changes will limit the size of a mobile app. One cannot start with a small app and let it grow, and grow, and grow as we did with desktop PC applications. Every so often we have to re-design the app, re-think our basic assumptions, and re-build it. Mobile apps will remain small because will be constantly re-writing them.

 I recognize that I am building a house of cards here, with various assumptions depending on previous assumptions. So I give you fair warning that I may be wrong. But let's follow this line of thinking just a little further.

If mobile apps must remain small (the user interface portion at least), and mobile apps become dominant (not perhaps unreasonable), then any programs that a business uses (word processing, spreadsheets, e-mail, etc.) will have to be small. The world of apps will consist of small UI programs and large server back-ends. (Although I have given little thought to the changes for server technology and applications. But let's assume that they can be large apps in a stable environment.)

If business use the dominant form of computing (mobile apps) and those apps must be small, then business processes must change to use information in small, app-sized chunks. We cannot expect the large, complex data entry applications from the desktop to move to mobile computing, and we cannot expect the business processes that use large, complex data structures to run on mobile devices.

Therefore, business processes must change, to simplify their data needs. They may split data into smaller pieces, with coordinated apps each handling small parts of a larger dataset. Cooperative apps will allow for work to be distributed to multiple workers. Instead of a loan officer that reviews the entire loan, a bank may have several loan analysts performing smaller tasks such as credit history analysis, loan risk, interest rate analysis, and such.

These business changes will shift work from expert-based work to process-based work. Instead of highly trained individuals who know the entire process, a business can use specialists that combine their efforts as needed for each case or business event.

That's quite a change, for a mobile device.