Live version: https://daattali.shinyapps.io/cfl-vis/
Code: https://rstudio.cloud/project/220158
This app was written in 2015 as a submission to Canada Sports Hackathon. It uses play-by-play data that was publicly available as CSV files to visualize the progression of a football match, by showing the passes, rushes, and touchdowns (when a touchdown happens, a youtube showing the highlight pops up automatically*). You can change the speed of the playback, and jump to a certain highlight.
I saw a contest submission yesterday about NHL play-by-play and it reminded me of this old app, so I figured I'd submit it to showcase! Code-wise this app is not amazing, for a few reasons. 1. It was built in 2015 and shiny and R have matured a lot since then. 2. I had less than a year's experience with shiny at that point and have not developed many good shiny practices yet. 3. It was developed under the deadline of a 48-hour hackathon with minimal sleep while caged inside a giant room fueled by pizza, which helps eliminate good coding practices even more 
With that said, I think one great reason to showcase this app is to show that a shiny app does not have to look like a shiny app. It can be served as an example of the diverse range of things you can achieve with shiny. It has a very custom look and feel, for example the "playback speed" and the long timeline are both slider inputs. And the main page does not look like a shiny app at all. This app makes some use of javascript to handle clicks and events, perhaps a bit too aggressively (there may be a few instances where a pure R/shiny solution was possible).
Unsurprisingly, this was the only submission out of all the teams across Canada that used R/shiny. Perhaps more surprisingly, this submission did win first place. Unfortunately I don't remember where the public data was taken from, and at the time I did not think of being organized enough to record that information. 
Team members: Tony Hui, Ogan Mancarci, Jonathan Ho
* The Youtube videos are actually of random matches because we didn't have time in the hackathon to deal with the legal and technical issues of uploading the actual real highlight matching this event