One of my friends is a stock market freak. A little while ago he learned started trading options.
One of the main indicators for his decision making is the volatility of an underlying stock price. This means that he is looking for stocks with great daily percentage gain or great daily percentage loss.
The only downside with this method is that there is no place without paying where you can get an overview of all the percentage gain/los for a list of stocks.
He mentioned his problem while we were drinking a beer in his backyard, so I did what every good friend would do. I built him an application which would connect with his brokers API and pull all the data he needs. To make it easier I used vuetify to put all the data in a clean interactive dashboard.
BONUS: Since my friend has no programming background I wrote him a nice .bat executable which starts up a local server and opens the application in chrome.