Backstory: Our world is advancing in personalization and customization. One of my (first world) frustrating issues is adjusting the shower temperature, it's a repetitive and I generally want the same temperature every time.
The Idea: A voice recognizing smart shower.
Deep Dive: You would build an attachment for existing showers that would use voice recognition to determine who is asking to turn on the shower and find their last desired temperature and start the shower at that temperature. The device would let the user know when the desired temperature is reached.
On an environmental note, this would help eliminate the excess use of water; notifying the user when their ideal temperature is reached. Also, you could build in features to report water and electric (heat) use per person. The idea is to reduce our overall water and electric waste.
Validation: In the future there will be winners in the voice recognition/home space. Building this device to work with multiple vendors help it succeed and possibly be bought by a bigger company.
Monetization: Similar to other physical purchases, watch your margins. There is a small monthly or yearly subscription option with a robust dashboard offering electric and water usage stats.