Birds Bumping into Your Windows?

We have vivid memories of a bird that repeatedly bumped into the kitchen window in our childhood home. It was genuinely heartbreaking and a hard memory to forget. We'd never heard of "bird deflectors" until we spotted a recent post on Daily Danny. Have you had experience with bird bumping, bird sticker deflectors, or any other tips to help the poor souls?...

Apparently Danny spotted these palatable bird sticker deflectors on a window in NYC. His goal is to make something similar for his own windows. Have you ever seen anything like these? Any good sources?