I think this is a truly terrible idea. First, headstones in graveyards are the opposite of offensive. They're memorials. That they're physical and long-lasting are important parts of that.

It would also require loved ones to have smartphones (not everyone does) and to run a particular app (which is intrusive) in order to honor their deceased. It means that there will be living people excluded.

> without disrespecting the graves

I think it would be disrespecting the graves to do this.

> rather than constantly in your face.

If people are so offended by headstones (I suspect few are), they can just not go to graveyards.