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https://play.google.com/store/apps/details?id=com.jimclark.bdo.bdostacklite
https://play.google.com/store/apps/details?id=com.jimclark.bdo.bdostack
The penultimate failstack optimization calculator. Supports cron stones, PEN enchantment, deleveling costs, jewelry, failstacking on greens/rebleth!