Software re-use has gained popularity and success due to technologies like Object Oriented Programming. Software classes and methods can be re-used based on their documented parameters and functionality.
The emergence of mobile apps over the last few years offers another level of re-use, that of whole applications. Instead of re-developing the functionality of an app (e.g. Google Maps) the app can be invoked by passing control to the app, providing it with a valid input (e.g. an address.)
Marketimpacts.com developed a series of Android apps based on applicaiton re-use. The Quickclick Locale series of apps uses the Google Maps API to map the locations of various types of places such as ATMs, Restaurants and Shops. The value added by Quickclick is an easy to use front end and app icons for different types of places.
To our surprise, there seems to be some resistance from other developers to app re-use. The only negative comments the Quickclick apps have received complain that the app is passing control to Google Maps to do the mapping. Certainly, we could have created our own maps. But why? Are we really smart enough to out-develop Google? Would we really want to scramble to update our apps with new mapping capabilities to match Google? We think not. Google themselves promotes the idea of app re-use.
App re-use has some powerful advantages:
Lowered development costs: App functionality can be had for the cost of implementing a siimple interface to the app to be re-used.
Automatic upgrades: When the app you're re-using is upgraded, your app automatically benefits.
Higher quality: It's unlikely you'll be able to duplicate all the functionality of an existing app focused on a specific niche.
Leverage of user knowledge: If the app you're re-using is popular, many users will already know how to use it. This is certainly the case with Google Maps.
Access to complete app functionality: Some apps, including Google Maps, provide only limited functionality via an API (Application Programming Interface). By passing control to and re-using the entire app, your users gain access to full functionality.