After Wal-Mart Stores Inc.’s back-to-school shopping portal “Classrooms by Walmart” proved a hit last year—about 35,000 parents registered for the site with their Walmart.com accounts—the retail chain giant has brought it back for 2013 with enhancements.

In addition to providing classroom and school supply lists that parents can use to shop for their children, Classrooms by Walmart this year includes school uniform lists, Spanish-language lists and the ability for a shopper to earn up to 4% cash back for her school while shopping online, Wal-Mart says.  Shoppers also receive free shipping on any Classrooms by Walmart school uniform or supplies purchases, or they may place online orders for pickup in stores.

Classrooms by Walmart is part of Walmart.com. Parents can log into the site using their Walmart.com accounts, search for their child’s school and teachers and buy items online or print the lists to take into stores, the retailer says. Last year, about 16,000 schools submitted supply lists to the shopping site, a Wal-Mart spokesman says. So far this year, 40,000 schools have submitted lists.

Walmart.com has long been selling school uniforms. But with the addition of school-submitted uniform lists, the retailer this year found new suppliers to stock exactly what the schools require, the spokesman says.

In the cash-back for schools program, Classrooms by Walmart shoppers earn 4% back on certain products purchased on the site, the retailer says. They may select their schools before shopping and track the funds they raise as they go. Additionally, cleaning products brand Lysol this year is awarding the schools that raise the most funds between July 15 and October 31 cash prizes totaling more than $50,000, Wal-Mart says.

An engineer with seven children who works in Wal-Mart’s research and technology division, @WalmartLabs, came up with the idea for Classrooms by Walmart in a “hackathon” event last year, the spokesman says.

Wal-Mart is No. 4 in the 2013 Top 500 Guide.