This idea was conceived trying to contemplating a one general trend and one significant challenge in mobile.
The challenge is that, despite the opportunity for innovation provided from few barriers to building and deploying apps, App stores have become flooded, making discovery and management difficult & time consuming for the user. Additionally we see a lot of duplicated functionality across applications (think Retail, Events/Venue Finders, Restaurant, …) i.e. the concept just doesn’t scale well.
The trend is the move towards deeper integration into the platform, taking the true advantage mobile such as better understanding of your current context, interests and being available when needed. The most obvious examples are the Personal Assistants offered by the 3 major players, giving you information based on interests and intent e.g. Google Now provides you with a card of near-by products that you have previously searched for.
But mobile is likely the place your audience are spending their time and chances of your App being discovered, downloaded, and used (enough times to become useful) are low. This is where the idea of App Extensions/Plugins come in – the idea is simply to allow extending of existing apps that users have, understand, and use. As a rough example; you could consider Passbook and Wallet as extendable Apps, allowing companies to have loyalty cards without adding cognitive load on the user (I imagine Starbucks will eventually opt for this solution in the near future).
I imagine this working with the user adding extensions at a platform and/or app level to incorporate new data sources for their preferred apps (not to dissimilar to Intelligent Software Agents as previously discussed). E.g. Instead of downloading a be-spoke App for Burberry, Sophie downloads the extensions – this extension integrates into Google Now (presenting offers in close proximity) and Pinterest for browsing and pinning.
And the thing is that I don’t see this as something that will happen in 3 years time but something that is happening now.