One of the greatest contributors to literature in the 20th century was the ballpoint pen.

Still early in the 21st century, but my bet is that the smartphone (not the Google/Apple versions) will be one of the greatest contributors to individual freedom.

If you read about the innovation of the ballpoint pen, it was invented in the late 19th century, but took decades of focused engineering to create the Bic ballpoint pen that we all know today.