I don't really watch stuff on the website I use my decoder.
What Showmax does do is keep track of which episodes you have watched with a tick mark next to watched episodes, so if it can do that it can surely keep track of the shows you are watching as well.
It might be related to the fact that Showmax content is not (currently) downloaded or stored on the Explora hard drive but a work-around should still be possible. The Showmax website does keep track of what you are watching so the information is already stored on your profile.
Octo-LNB to 24-1z/5.2 switches. Explora1 (Prim) & HDPVR 2P (Sec), Samsung 55" UA55F8500 Smart 3D LED TV, HDMI picture & audio via Onkyo TX-NR626
receiver. Explora 2 in bedroom, HDMI picture & audio to Samsung 32" UA32F5500 Smart LED TV. 100Mbps M-Web fibre (OpenServe).
When you go to Catch Up, it displays all the programs that you are watching at the top of the page.
Showmax on the other hand has nothing like this which means you have to scroll through all the stuff you don't want to see. Sure you can narrow the results by selecting Sci-fi, Comedy, etc. but surely they should implement some kind of favourites system so you can quickly access the shows you want to watch.