Count forwards and backwards with the Super Sequencer, including decimals and negative numbers. There are 3 speeds - slow, medium and fast. From Ambleside Primary.
http://www.amblesideprimary.com/ambleweb/mentalmaths/supersequencer.html

The Multi Sequencer displays two sequences simultaneously. Click on [Instructions] and then [More] to get some ideas how you might use this.
http://www.amblesideprimary.com/ambleweb/mentalmaths/multisequencer.html