My point is, that using images to display math (or chemical) equations is pretty outdated. Apples iWork, dozen of Markdown editors and millions (well, I guess of websites are using MathJax to render formulas, which are mostly entered as LaTex. Only recently I found, that there's an even better way called KaTex. KaTex is a slightly modified version of LaTex, which is capable to render mathematical as well as chemical formulas. A comparison of these two techniques (and some more) can be found in this blog post: https://www.intmath.com/blog/mathematic ... tions-9915. The rendering is done online on https://www.mathjax.org, but the LaTeX input is performed locally.

Personally, I'm using

*Equation Maker*(App Store) to either generate LaTex for MarkDown or images for Mellel. Beyond that, there is

*xformula*. The macOS version is X.15+, so I can't say anything about it, but the iOS version looks quite solid.

Kuulest