Comment by collingreen

This thread is a really really good example of why this kind of question sounds good but can lead you astray. So many folks have been generous with their answers here but a huge portion of them have multiple replies with existing solutions that were a simple google away, which means they thought of a neat idea but they definitely were not desperate enough for a solution to even search for one let alone pay for it.

Those kinds of ideas can still become real businesses, especially if you have a great way to get awareness of your solution out to people who aren't actively looking for that, but you're better off trying to find problems where people have tried throwing money at every solution out there and are still yelling for help.

Tl;dr try to sell "pain killers" not "vitamins".