the author writes that "It's perfectly permissible for Haredim to write on the sand on Saturday..." this is inacurrate. There is no Biblical prohibition however it is forbidden Rabbinically. As #7 wrote these inventions are used for hospitals and the like - where there is a need for doing actions not normally allowed on shabbat - but we want to minimize the violations.
Zimbabwean charged over killing of Cecil the lion (Reuters)
from the article: How to be religious - and enjoy a Shabbat espresso