Here is a site that my Grade Two students love. It is called Tutpup and is a place where students are matched up with other students from around the world to play maths and spelling games in real time. There are several games to choose from, each with multiple levels.
The maths games cover addition, subtraction, multiplication, division, algebra, and a mixture of those skills. The spelling game involves students listening to a word and spelling it before their opponent.
The site is great because kids can work at their own level, they can learn about other countries (we like to look on the world map to find the country our opponent is from) and the “race” format of the game is very motivating!
Students can even play at home!