Life Science for 2nd grade has passages all about science topics! You can set up users and track their progress or just play as a guest.
Reading Comprehension-Fiction for Kindergarten and 1st Grade has 20 stories about young children's daily life. It is set up just like Life Science and allows for your to add users and track their progress!
Inference Ace would be great for your higher level readers. I love how it will give an extra clue if an answer is not correct and allow the student to try again!