I actually did something similarly stupid in college; for an embedded development class, my team needed a final project. I proposed a hat for the blind, with distance sensors and buzzers on the inside to inform distance from the walls and such. We also used black conductive thread on a black hat, so it was impossible to work with except for the girl who threaded it in the first place.
Easily the professor's favorite project, and I guess he still uses it as an example for future projects (and at some point he had some team extending it into some kind backpack?)
Later a friend working at a retail store selling products for the disabled contacted me about the project; apparently his boss was interested.
What no one acknowledged is that blind people are not walking into walls... the cane is far more practical, efficient and effective tool than this thing could ever be.
I had meant it to be a joke.
The best thing about it is, the people who need and want the device aren't the ones walking around reading their phone, it's the ones who can't help but mind someone else's business - and this merely feeds their need rather than satisfies it. So there will be an never-ending market of unsatisfied busybodies.