I have been introducing more music learning games recently at my studio, to the great joy of my students. The newest addition to the studio is a set of Japanese puzzle erasers, full of cute, colorful animals that kids will love! These are perfect for practice at note naming and chord spelling, as they do not harm the piano keys.
In the closeup example below, the erasers spell a C7 chord.
These erasers would be a great tool for kids to use at home to practice with their flashcards. Here is where I bought mine: