It really depends on the OS and OEM in term of updates. If you have iPhone 4, you can’t install iOS7, which means a bunch of apps are off limits to you.

This is why closed ecosystems are vile and Stallman was right in vilifying Jobs in the end. Android is definitely less bad in this respect. I have a handset that runs Android 4.1 (don’t want to upgrade to 4.4 because of its asinine treatment of SD storage, so I’m holding out for the next version that is supposed to fix some of that), and I can run 99% of apps even though it’s a two-year-old OS.

Though I have to say that other than Maps and Talk, I don’t use a whole lot of Google apps.