It’s called “iModelKit”. They have a scale caluclator, all major paint mfgs color chart, ANA colors, FS colors, RLM colors, RAL colors, paint mixer, notes, etc.
I use it. The paint colors on the app are not accurate as far as mixing is concerned. What it says you need to mix to acheive a given color don’t work. I tried it alot on my Me410 and it was way off. I use it for reference only now. The pics of the colors are fairly close, but the mix feature is crap. But, like I said, I use it for color reference. It works pretty good for that.
Great app for sure. I dont rely on it for spot-on color swathces but its fantastic for cross-referencing colors!! Its my go-to source for cross-referencing RLM colors to manufacturer choices.