Reader Hannah passed along a deal she found on these Leapfrog School Quantum Pads. They are marked down to $7.99 on Amazon (from $29.99).
I am not familiar with this item but this is the description on Amazon:
“Introduce children to the magic of learning with Quantum Pad. When children touch the interactive Quantum Pad book pages with the included “magic” pen, they can bring math, reading, language arts, science, geography and history to life. Includes a sampler book. Each book in the Quantum Pad library is packed with engaging activities, games, stories and facts to help develop a love of learning. Book and cartridge sets sold separately. The Quantum Pad system also works with all LeapPad books and cartridges (sold separately). Requires 4 AA batteries, not included. Designed for students in 3rd grade and up.”
Amazon has a few books priced as low as $3.99. Shipping is free with Prime.
I also noticed Leapfrog.com has a handful of books priced at $3.99. They are mostly bilingual books- just type in Leappad to see them.
Code WINTER20 worked for me for 20% off but shipping is $4.95.
Thanks Hannah!

I think is the predecessor to the Tag system.
My 9 year-old used one like this after he graduated from the leappad.
His enjoyed it, especially on trips – although it is more to lug around than the Tag system.
If you buy this, I would recommend getting any books available now as it will probably be difficult to find them. Craigslist and yard sales might be good sources.
Thanks for the tip. Just purchased two of them and some of the books.