I don't know what an "action bar" is, though this looks like a notification. Does it appear on the right (typically system notifications) or left (app notifications)?
The problem is that there are literally millions of apps, so unless this is a well-known one the odds of anyone reading this knowing what it is are slim. If this is on your own phone pull the notification slide down and you'll be able to see what it is. If, as is more common with these queries, it's on someone else's and you've just seen it in a screenshot, the simplest answer will be to ask the person whose phone it is. You could try a reverse image search on the image you've uploaded and see whether that finds anything.
If you want my guesses, games and gambling apps are the first things I think of when I see this, but it could be almost anything.