Well It works for your issue.
Yes in ios we have different sounds for different apps, but it depends on the app developer, if has a ringtone builtin or we can choose what we want.. It's there in android also..And no.. The ringtones don't keep reminding us.. But again, depends on the developer, he can add functionality of reminding you from time to time..
But the light is only useful when you don't have it with you all the time, which is in your case...
You say you have 2 phones, suppose you had only 1 then I think we wouldn't have this issue... Ok, just do this for a day.. Turn of your light in your personal phone for a day.. And tell me how does your day go... If it's possible for you to (possible meaning not related to your phone , if it doesn't affect your daily work or anything)