Just pick something of your interests. Digg into the material, as far as you can and write about it. What's clever about the product you have chosen? What's not so good in your opinion? Can you see or find similarities to other products (maybe even from very different category)? What's unique about it? Etc.
Another way could be to grasp Reddit or StackOverflow for questions, then research them. Now you have a concrete goal. It's maybe easier than asking yourself what others may interest.