Thats why XBMC rocks. It has 2 views that is perfect for this.
1. Recently added
This is where you see anything that has downloaded and added recently XBMC. Usually the last few days worth of stuff will be in here.
2. In Progress TV shows
Now this one is a beauty. Sometimes TV shows are far ahead of where I am, and sometimes I forget about a show which had a new episode but gone past my recently added shows. These I can find all in here. It shows me shows which I have started watching, but haven;t finished.
Much better than an app, because I can just go plonk my ass down infront of the TV, and at my fingertips with the remote control look at what is ready to watch, either new or in-progress tv shows.
You can even setup smart playlists to show you exactly what you want. I have one view set to only show me recent shows from my favourite episodes. I've also got a PseudoTV channel only for these, that plays the shows in order, and another channel for all new episodes, played in order...