I would like to thanks Andrea Solís Tejada (Andy k566) for helping me with the design and debugging of the app.
if you are tired of having to switch gears and heroes to get the minimum cost and then look if you have enough resources to upgrade, it's all right I been there for a long time but I came with the solution.
KOA RSS Calculator is here to help you get the exact amount for resources that you need to upgrade buildings despite heroes and gears.