Future expansion

As I can see, the more products you suggesting, the more money you can make. So, I'm doing a new project now, some sort of slideshow creator/viewer. It will be released in two versions, Lite and Pro. This is for the purpose of education, I want to know, how Lite versions could attract users to more powerful Pro versions. I hope to release this project in two-three weeks, the main problem for me is UI and design.