But I had my perfect watch but unfortunately Casio does not produce it anymore, let alone improve it.
Its battery lasts for 5 years and yet can give accurate time and temperature. It can even predict temperature anywhere in the world anytime, with a world map as well.
With its alarms, it can become an organiser but with the extra information of temperature which is missing in many organisers. I used it to plan my trips to Mecca and Hongkong. I cannot find the information from my PC in those days. Even with current PC or Windows tablets, it is difficult to get the data and therefore takes too much time compared to the information that I can get from my TS-100 watch.
Even my smartphone is not that smart as well. Even with so many keys, they are difficult to find the data that I need quickly with sufficient accuracy for immediate use. A watch is much easier to see, take out. Even with only a few buttons, we can get the information much faster, after all, we don't change cities that much. Once we target a city, we will get the information from that city as well.
The secret to the success of the TS-100 is the use of database instead of downloading the data. World maps and temperature data is very useful and widely available. We don't need detailed data. By providing data for various places on earth, we can extrapolate to nearby cities. After all, all the nearby cities have similar temperature and time zones. I can't think of a way to improve it. It is even waterproof up to 100m. Casio destroyed this watch by providing thicker watches that don't have builtin database, relying on calculations to get the information such as tides and moon phases, which are of limited use and easily noticeable by people who are really into the business of noting tides and moon.
We can improve the TS100 by making it lighter and the pictures clearer. If you add extra sensors to it, its battery life will not last long so they are best left out.Any power hungry calculation mode should not be included but easy downloading of data can be added to the watch. We can add an encyclopaedia to the watch that are tied to the temperature, time and location that we set ourselves, with offline maps for better location. It should not transmit any data, just receive them, like the RFID. It can even receive power wirelessly when it is receiving the data.