Most apps have (in the 3 bars do down menu) an “about” section that at least give details of the current build, often a link to the developers web page, help, and even a link to a forum like this get satisfaction one.
I’m on the beta version since I downloaded that and it should get updated automatically. If I go into the app info from the All apps link in my Android home screen, I can see the version is 4.0.0b1. It would be sensible to find that from within the app.
Alongside this, you’d need to show the current version somewhere on the newsblur site that we can find easily. Being on the beta, and with issues that I know will be fixed in the next build, I’m keen not to miss an update.