A little tool to illustrate changes to income tax under a Labour government in the UK.
Obviously income tax isn't the full picture for a party's taxation plans, but as one of the 'big factors' for individuals, I think it's important that people have a decent idea of how they will be affected.
Clicking the menu in the top right and then 'Advanced' will show a breakdown of the taxation under each marginal rate.
I'm not aware of anything similar based on the tax plans of any of the other parties,
Disclaimer: I am involved with the group who built this, although my involvement on this tool itself was minimal.