Often I am annoyed that the most recent update of an application (on my mobile device) performs worse than the one before, but going back seems impossible!
I would like to have an app store which allows to browse through versions of an application, and allows their rating in regards of bugs, features and performance. So I can choose which one fits best for me.
But this is not in the interest of the industry, that wants the consumers to buy new hardware regularly. Old software would run fine on old hardware, it might be a problem to support multiple versions of protocols to web-services, though. Anyway, I think it’s goog to keep using a device, as long as possible to save the environment.