This is a editable Microsoft Word product. My students mark their nightly reading on a 100 tracker and once they read 100 nights they get a brand new book from a treasure box in my classroom. I tape one of these labels into the inside cover of each of the new books and when a student chooses it, I write their name on the label with a sharpie.
You could also change it to reading 100 minutes, 1000 minutes, 100 books, etc. Another alternative would be to print off on cardstock as a mini-certificate or as a coupon for something else.