Yeah i´ve seen it but it has some limitations because tradingview doesn´t provide historical bid/ask data so everytime a new symbol is loaded or browser/script is reloaded, the previous symbol data is lost but yeah, it´s a cheaper alternative for anyone who wants to try footprints.
Sierra is IMO a nightmare to set up and the learning curve for the software is very high so it took me a good while to set everything up the way i wanted and i had to reach out to other more experienced Sierra users for guidance. But once everything was set up, the charting worked great and you have all historical data saved as well for analysis.
There´s this new platform which i found recently called
GoCharting which is all web based. They currently have a beta site which has orderflow tools even for stocks like footprints, imbalance and cluster layouts. Pretty cool!