Backstory: My girlfriend, Julia, is always forgetting her cellphone. We'll be going out for the night and nearly at our destination, she'll notice it's gone and insist we go back to get her phone.
The Idea: A bluetooth notification device for your car, home and office to let you know what devices or items you have.
Deep Dive: Similar to tile, this is a device to help keep track of your stuff. You would build a bluetooth module that would connect to any device and act as a geofence to display a light either green or red if the device is within range.
In future versions, you could build in a noise/chirp feature as well.
Validation: Tile has made a huge impact on people locating their lost items.
Monetization: You would charge a set fee for the device/hub, watch your margins! You could sell different packages with multiple devices for the car, home and office.