Earlier today the latest version Maths Rush for Windows Phone was submitted for Marketplace review. This release includes online high score sharing, improvements to the UI and a number of bug fixes.
The online score sharing includes leader boards for overall, weekly and daily for both the 50 and 100 questions games.
In addition a player can view his rank.
The next release of Maths Rush will include Live Tile support showing information such as the players rank.
You can download Maths Rush for Windows Phone here.