Backstory: It's hard to pick out home design items, especially with new trends popping up. It would be great to visually see what certain patterns and styles look like in your rooms before purchasing.
The Idea: AR home design app.
Deep Dive: You would build a home design app for people to visually see what their room would look like with different accessories. You could have a quick questionnaire to help determine their style. As people like and dislike items, you can build a profile of their preferences.
Validation: Houzz did a great job of doing this in the 2d space.
Monetization: You would offer to sell the accessories shown in the virtual room. You would take an affiliate commission on each sale.