Something like a mood ring that changes color when mold-causing moisture is present. ideally colors should get deeper in intensity the higher the moisture level and there should be a scale that tells you that based on the color, you are susceptible to mold. It could be on a strip that you could stick in various locations. 

A large ziplock bag to store big winter items like sweaters or even blankets that will keep them smelling fresh until you need them again the following year. 

A disposable liner for inside a toddler's potty would be a big help and would make cklean-ups easy. My 2 y.o. just pooped inthe potty for the 1st time and cleanup was difficult because it was sticky and gooey so it didn't pour out into the toilet easily. A disposable liner would take some of the mess out of potty trainig. And of course it can be decorative.

Here's what I need. My son loves sandwich wraps made with tortillas for lunch at schhol but there is no lunch container in that shape so I have to wrap it in foil or just put in a regular sandwich bag and hope it doesn't get squashed. A storage container for my son's wrap sanwiches or leftover corn on the cob, somewhat long and narrow is what I need.

Sandwich bags with school themed designs to include special days like Valentines Day etc. These can also double as treat/favor bags for cookies, snacks etc.