OK, so not entirely sure this is possible...
But trying to write an application so that I can run some code before any of the following activities are performed.
1) APK is downloaded from web and market launches installer
2) Install button is pressed on android market
Is it possible to intercept and prompt on these events, or has Google locked that stuff down quite tightly?
Using a BroadcastReceiver you can filter the android.intent.action.PACKAGE_ADDED intent. However this will only be after the two actions you describe, not before. And it will not stop or interrupt the installation.
AFAIK there is no way to do anything before or to interrupt the Market. And then we're even talking about another app than the one that's being installed ofcourse.
You can write your own custom installer for android app visit this link https://github.com/android-enhancement/android-alt-installer for further explanation.
This isn't an answer per se, but I can't find any commenting tool here. Sorry. I'm having this issue as well. I would like to be able to detect new application installs. I know it is possible - for example, the app Apps to SD posts a notification when you install a new app that when clicked opens a dialog to move that new app to the sd card. So far, all I've been able to figure is like this: manifest.xml:
IntentReciever.java:
YourService is then created and calls onCreate() then onStartCommand(). However, I haven't been able to debug this or successfully display any notifications from the service class, so I'm not entirely sure this works. I have gotten this to work for other Receivers like android.intent.action.BOOT_COMPLETED.