Simple OCMod extension adding support for percentage discounts.
On "Discount"/"Special" tabs you will see new column "Discount %"
When you set percents, neighbour field (Price) updates with discounted price value. Also when you change base price all discounts will be recalculated automaticaly.
Based on "Percentage discounts" by Jorim van Hove If you looking version 1.5/2.x, please check original module @ here, but pay attention that original module dont update discounts on changing product base price