Didax has developed a wide assortment of virtual manipulatives for mathematics educators to use with their students. The apps are free, user friendly, very intuitive, and work well with any program your teachers may be using for mathematics instruction.
Tens Frame (1-20)
Tens Frame (1-100)
Fraction Tiles & Number Line
Two Color Counters
120 Number Board
Base Ten Blocks
Place Value Disks
Prime Factor Tiles
Toy Theater offers a wide variety of virtual manipulatives for mathematics. This site includes tools that are challenging to find elsewhere.
Mathigon Virtual Manipulative Pad
Mathigon offers a single virtual pad that can be used to engage students in lessons requiring polygon shapes, tangrams, pentominoes, number tiles, probability, and other relevant and useful apps.