10ticks Mental MathsIt is great to hear that children are using 10ticks from home. Use this link or search '10ticks mental maths' to log in.
ScratchYou can begin to create projects online by clicking the link then create in the top left corner. It is also possible to download the program for free by clicking download at the bottom of the page
DuolingoDuolingo is available online and through an app. Though it is free, you will have to make an account for your child to access it.
Isle of TuneIsleoftune.com can be used on a pc for free. It allows children to create their own islands with roads, houses, trees etc and everything they put in it comes with a sound. Then you set a car driving down the road and when it passes each object the sounds play - in this way you can create musical compositions. There are some on there that some people have created already so you can see how it works. Note: app versions do cost.