I found this fun dataset (originally scraped here by planetsig) and thought it would make a great app while I was teaching myself how to use leaflet.
Found the corny vintage UFO gif on the GifCities search engine
complete.csv is the uncleaned data.
data_prep.R guides you through how I prepped the data for the app, including extracting colors with regex and dealing with messy/inconsistent location data.
within "appitself", you'll find app.R (the app itself) and the cleaned data.
www holds the gif and additional CSS/HTML files to make it look nice!