On a smartphone, the home screen is the prime real estate. It's where our eyeballs hang out. Metaphorically speaking, of course. No one is getting a screen implanted into their eyeballs - yet. On my iPhone 5 I have 24 icons in total. Here's the breakdown company by company.
- Apple (7) - Phone/Clock/Messages/Settings/Camera/App Store/FaceTime
- Google (4) - Gmail/Chrome/Maps/Hangout
- Facebook (2) - WhatsApp/Messenger
- Dropbox (2) - Dropbox/Zulip
Together with 9 singular apps from various companies / individuals, for a total of 24 icons on my home screen. The bottom row is dominated by Apple and Google at two each.
Looking further at my five most recent apps they are all communications app: WhatsApp, Hangouts, Gmail, Twitter, Messenger. A more normal weekday would see Maps and Chrome here, but probably not Phone.
All said, it's safe to say that my screen estate and usage habits are dominated by the big fish.
So much for eyeballs. What about money? I pay Apple. I pay Dropbox. I don't pay for half of these apps or for services tied to them. Compare this to my singular apps, for example IRCloud and Anki, where the only companies I don't pay are Twitter, Yelp and an experimental calendar app called Magneto, which I'm sure will either (a) cost money (b) shut down or (c) get acquired soon.
The saying If you are not paying for it, you're not the customer; you're the product being sold comes to mind. It certainly applies here, but is it meaningful? I'm not sure. If I'm the product being sold, who am I being sold to? The stereotypical answer here is "advertising", but there's almost no advertising on mobile. What about network effects? Maybe I'm a node in a network which increases disproportionally in value with every new node, and it only makes sense to look at the network as a whole. What about good-will? Buy-in? Lock-in? Charter customers? Knowledge acquisition?
Whatever it is, it's interesting and scary  at the same time.
Which companies own your home screen?