I don’t even think one should trade when fully employed.
Still if you want to, then you can keep one tab open on your computer and switch tabs when required.
Actually this is not a major work . Apple has an excellent eco system where in if you have an app in one platform itll automatically work on every other apple device . (Almost )
I think zerodha tech team not launched watch app may be due to insignificant number of users else with minimal man hours one can easily release ios watch app if you have an ios mobile app .