Nutrient mixture apps

I've found 3 apps so far that look like they'd be helpful for calculating hydroponic nutrient mixtures. - iFertigate is a smartphone app put out by the US government that looks quite thorough, but unfortunately, it no longer seems to be available. - Hydrosolver is a very promising console tool for Linux. - ScienceHydroponics provides an online solution that seems pretty capable.

I'm noting these here for future reference, but for now, they seem a bit more advanced than I'm really qualified to explore. I think a better plan for now is to follow the standard Masterblend formula, and then revisit these once I have a better understanding of what I'm doing.