In-app update notification

Today, when I started the game greedy spider, there was a dialog box telling me there was an update and a link to get it from the market. I'd like to know how can I do that?

How can you change the app (like adding a dialog box at the opening) without pushing an update to the market?

Thank you!

Solution

There is no straightforward way of doing it.

I can imagine something like that:

There is an unofficial Market API which you can use to fetch the details about your app and check the version How to fetch Android Market data when there is no API?
You can start your own web-service which would return you the current app version

After you've fetched the new app version from some external source, the rest is pretty easy - get the current installed version from app's PackageInfo and show the dialog if it's lower that the newest one.