cryptodrop.net
There's been a lot of discussion over on 
The site tracks changes of cryptocurrencies on Coinigy and sorts them by biggest drop to biggest rise. You can filter the results across a time period as well, so as to only show percentage changes in the last 5 mins, 10 mins, 1 hour etc...
At the moment it only supports symbols on Bittrex but if there is demand for more exchanges I'll add them in.
I only just released the site yesterday so I'd love to hear your feedback on it. If you have any suggestions or features you'd like to see, please post them here! As I release updates to the site, I'll make a new post here to let you know the details.
How the site calculates percentage changes
Percentages changes for currencies are calculated by taking the highest closing price and the lowest closing price in the given period and calculating the percentage change between them. I considered calculating it based on the first and last prices in the given period, if this method of calculation is preferred I'm happy to change it.
The site is totally free to use. I don't have any plans to charge for it, I didn't write it for money.
I'll try to implement highly-demaded features as soon as I can but I'm a busy uni student so please be patient! If you want to see a feature added, please let me know and I'll implement the most-demanded features first.
Happy trading!
Edit - New features added!
- Added audio alerts when new data comes in. A sound will be played if cryptodrop.net isn't the active window/tab
- Added a button to mark rows as seen and move them to the bottom of the list
- Added settings to turn off audio alerts and auto-refresh
Future features planned:
- Links on each row to go to the Coinigy market for that symbol
- Add more exchanges
- Add custom filters, ability to filter based on exchange and markets
- Add more options for audio alerts
- Audio alerts when new data is obtained - Done!
- Feature to mark symbols as "seen" / move them to the bottom of the list - Done!