This site allows you to create trading cards for any purpose. you could create cards filled with historical facts about a person (fictional or real). You could fill the card with information about a landmark or location. you could even use this site to create cards for a game. To sum it up, this website could be used to study or play a nice card game that you just created.
This is a website that teaches math. It has flashcards you can quiz yourself, or you can make your own. It also has many educational games, having to do with math. It also has math worksheets you can use for more practice on a topic.