Book Adventure is sponsored by Sylvan Learning and offers readers prizes for reading. Students earn points for taking quizzes and then spend their points in the Prize Library. Prizes range from temporary tattoos to ebooks, to candy and even prizes created by parents or teachers like eat lunch with a friend or extra TV time. Parents can monitor their child's progress and even look for books for their child to read next. Teachers can create reading lists for their students, create contests and teams, make quizzes, and send reading reminders to their students. Reports are also available and can even be printed to send home to parents. Book Adventure does not have as many quizzes as AR, but it is free and could still be a way to entice students to read.
If you are not a fan of quizzing students for every book they read, then Reading Rewards may be the alternative you are looking for. Reading Rewards is a free website started by a mom who wanted to encourage her kids to read more instead of playing video games or getting on the computer. She developed Reading Rewards as a way to reward her kids for the amount of time they read, and there is no quizzing involved. To get rewarded, users log and and record how many minutes they have read. Parents are then asked to verify that amount of time. Once this has been done, users earn RR Miles which they can then redeem for rewards. The rewards are things that parents and teachers can provide like a movie night at home, family game night, a sleepover with friends, prize from a treasure box, or extra computer time. To keep users motivated, they earn badges as they go through different reading levels. It does require a bit more work on the part of the parent and teacher than AR or RC does, but Reading Rewards is free and it could be just the motivation a child needs to encourage them to read.
If you like the quizzing option, then QuizWik might be the way to go. QuizWik was started basically by some disgruntled AR and RC customers who felt that AR and RC were getting too pricey. They developed a wiki of sorts to share and use short teacher made (TM) multiple choices quizzes for children's books and offer it for free. (You can read more abot QuizWik here.) As of the day of writing this post, there were 43,852 TM quizzes available on QuizWik and it's a free site, although there is a sister site that has started up that is subcription based. It's called ReadnQuiz, and boasts that it is a tenth of the cost of AR. It has 30,000 quizzes available.
While none of these three options provide everything that AR or RC did (how could they for free?), they could be decent alternatives, especially if you feel your students really need some type of incentive or way to keep track of what they are reading and how much they are reading.
"AR" and "RC" are trademarks of Renaissance Learning and Scholastic, respectively.