Figure 9.16: The Hive Active Thermostat heating controller and smartphone
app (Images: British Gas).
Some devices may not support any user interactions at all (see figure 9.17).
Some devices may be simple sensors which simply provide data to the service,
as in an air quality monitoring system. In this case, you may simply hand off
all functionality onto a single mobile or web app. Although the overall service
may be complex, the web or smartphone UI in this case is in some ways
simpler to design as there is only one interface to consider. (Chapter 8,
Interface and interaction design, considers the pros and cons of handling
functionality via a mobile device versus a specialized embedded device).
Figure 9.17: The Greenbox garden irrigation controller is entirely controlled
by a smartphone app (need alternative – 403 on greenboxhq.com).
When key tasks are available across multiple devices, users may still be able to
use the service even when some devices are unavailable. For example, the
Withings smartphone app can use the onboard accelerometer to measure
activity, so even if the user has forgotten their dedicated activity monitor, they
need not lose data (see figure 9.16).