Alas, most probably the answer is: No.
Reason: Android's App model.
An app exists of rather loose coupled components (Activities here) that may be launched independently from each other. Only when the main activity is launched as a separate task an entry in the recently launched list is created. Other apps can also launch an external activity (of another app) that does not count towards that list then.
This happens mostly when you dont launch an app from the launcher:
- You click a notification (missed call, sms, calendar event, ...)
- An app opens another app (twitter app -> browser)
- follow a link in an sms -> browser
- select an image in an app -> open in gallery
- open youtube from a browser link
All those 'opened' apps count as part of the opening app and not as a separate instance (most likely)
I answered a similar question here: Function of back button after opening URL from (Twitter) application
Info about the underlying architecture: http://developer.android.com/guide/topics/fundamentals/tasks-and-back-stack.html