There is a vast range in the complexity of these widgets ranging from simple animations of stepped processes, through to interactive 3D simulations.
However, all aim to allow users to progress at their own pace and construct their own understanding by modifying parameters and exploring the consequences. Examples include algebraic animations, virtual mathematical tools (eg Abacus), graphics calculators and 3D shape explorers.
Gamelearn is the sole developer of widgets for Hotmaths and over the last few years has produced several hundred Flash widgets and is now beginning the journey of converting these to HTML5.
We are also considering this an opportunity to improve the widgets both in terms of usability and educational effectiveness.