The number 9 can be viewed differently depending on where you are. In China, it's considered positive because its sound resembles the word for 'long-lasting'. Take a little trip across the sea though, and in Japan is considered unlucky as it resembles 'pain'.
If you are using ProCollage though, 9 is the number of photos you can add to your photo collage. The app not only comes with prepared layouts, it also allows you to 'FreeStyle', meaning you can arrange them as you like. Add some colorful text, and you have the perfect assemble of photos. Today it drops from $1.99 to $0.99!