iPhone app - suggesting that the user update to the latest version

Question

We currently have an iphone app in the app store. We release version updates periodically, about once every other month or so, sometimes more often. Most of the times, the updates are not large, just added bits of functionality, bug fixes, etc. Sometimes however, there may be major changes (so far it had happened once, about a year ago and it's about to happen again).

When major changes do happen, ideally, I'd like to get the users to update to the latest version. I know that there's no way to automatically install the update. As the app communicates with a web service to receive its data, I can use that service to check for the latest version and, if it's not the latest one, I can alert the user that a newer version is available and prompt to update. If the user chooses not to update, I have to options: (1) let them continue running the older version, or (2) effectively force the user to update by blocking the app functionality if it's not the latest version.

As the app requires back-end web-service, usually for major app updates the back-end needs changing. Sometimes these changes render the back-end incompatible with the previous version of the app. The previous time this happened, I had to set up a separate back-end for the new version (I now have to two web apps running on the server: for v.1 of the app and for v.2). While theoretically I can continue doing the same - setting up v.3 and so on, I would much rather prefer not to and force the update on the user.

Now, technically it's quite easy to set up. However what is Apple's view on such behaviour? Could they reject an update because of this? Any experience on this front? Thanks in advance.

Answer 1

It depends on the time frame of your transitions. We have a customer who exactly required the behavior you describe. We can send the client application two signals: should-update and must-update. When the client receives must-update, it will no longer allow the user to run. We have transition periods and tag the breaking changes, so maybe the active backends right now are e.g. V6, V7 & V8. We give users enough time to transition.

Answer 2

The Chase bank app forces you to update when an update is available (or else you can't log in). I think it's pretty annoying from the user's perspective, but Apple has certainly approved updates that do exactly what you're describing.