MMM develops projects from scratch in a minimal environment. Perhaps that's the hard way, but it's straight-forward, basic, and does not require fancy tools or special software. The end product has a "homey" look and feel.
We do take advantage of services offered online, several listed in the explanation text "About Apps" such as Adobe PhoneGap Build, Android Asset Studio and CSS Button Generator.
Currently, Ms MathMaster herself uses an HP ENVY 23 PC and Asus laptop, both running Windows 10, a Samsung Android cell phone, and Samsung 7" tablet. We use simple text editors, Wordpad and Note pad. We use Paint Shop Pro to hand-produce most of the grapics and use what we find for free on the web.
This web site is hand-coded with html5 and CSS. It is "responsive", meaning it will change styles when viewed on a mobile device. When building web sites, iXWD prefers to use WordPress for the vast diversity of designs available, huge arsenal of plug-ins to add functionality, the speed at which one can build, and the quick support of the WP community.
MsMathMaster and iXWD are not professional businesses. We are learning projects and teaching tools. We are here to increase our skills and share information with other beginners and students.