Why is BBC iPlayer task bar not visible?

I've downloaded the latest BBC iPlayer android app from the Google Play Store (7 December 2014) and installed, but when opened I cannot find how to bring up the task bar at the top. I therefore have no way of selecting channels or categories. All I have are the large thumbnails for individual programmes plus (on the top right) the small icons for downloads, search, and favourites. Descriptions of the latest app say it definitely should have the channel and category browse options, so how do I access them?