Plugin for offering free gifts based on % of cart total with Woocommerce

Hello,

I’m looking for a plugin that would allow me to offer free gifts customers can choose themselves based on a % of the cart total.

For example:

The percentage value is set at 25%, they order ￡100 worth of products, so are allowed to pick free gifts up to the value of ￡25 (or less).

Does anyone have a solution?

Many Thanks,

M.