If you're keen to get in on all of the holiday deals for apps in the Play Store make sure you check out AppSales which is available for free on the Play Store. This app is great for finding apps that are currently on sale and you can even track apps in a 'Watchlist' to keep an eye out for any app you are interested in getting. Not only is this app essential for getting good deals on the Play Store, it follows Android Design guidelines so is attractive and easy to use.
Have a read over at AndroidNZ if you want to know more before diving in.
Senior Consultant @Intergen All comments are my own opinion, and not that of my employer unless explicitly stated.