Amazon offers a selection of Baby Genius Sing 'N Move Kindle eBooks for free, as listed below. (Barnes & Noble has the Nook version and iTunes has the iBook version for the same price.) That's at least $5 under the best price for a hard copy of these books. The deals:

• The Wheels On The Bus: A Sing 'N Move Book for Kindle (pictured), Nook, or iOS for free
• Old MacDonald had a Farm: A Sing 'N Learn Book for Kindle, Nook, or iOS for free
• 5 Little Monkeys Jumpin' on the Bed: A Sing 'N Count Book for Kindle, Nook, or iOS for free