MacShiny is a purported "cleaner", "anti-virus", "anti-theft", "anti-malware" (a la MacKeeper) app which appears to be promoted in pop-under ad networks.
"Double click to install.pkg" is the dropper, "InstallerHelper" is the package contents which drops MacShinyFull found in "MacShinyFull-SOURCE" which among MacShiny installs a few other Applications
Everything is written in Angular via Xamarin Framework.
The company's entire stack is .ASP NET. This was just a cursory dive into their code.
Full source available and unminified in the repo.
Some friendly tips, to deflate a .pkg file simply run xar -xf MacShinyFull.pkg which will drop everything in the working directory, often times when you encounter another PKG it could also be a directory.
In the present working directory unzip the files Scripts and Payload via:
cat Scripts | gunzip -dc |cpio -i;cat Payload | gunzip -dc |cpio -i