Made by Casio
The first invention by Tadao Kashio was the yubiwa pipe: a ring that allows you to smoke a cigarette hands-free and all the way to the end. Tobacco was expensive in war-torn Japan (because WWII), and people had their hands full of work, so this was exactly what the market wanted. With the profits from the pipe, Kashio could fund the development of Casio's first electro-mechanical calculator.
High intelligence and flair for business combined with this sort of diligence could not have led to anything but the success Casio has achieved. The company has been the first mover too many times to mention. Let's skip the list this time.
Being the first mover has not sacrificed quality: many people still use Casio wristwatches they bought 40 years ago, and they have gained the trust of NASA, numerous special (and non-special) forces, law enforcement, paramedics, and so on. Another long list. The TL;DR is that all of these are damn good, pick any one you like!