I was searching for usefull chess tools, and I found must-have free chess tool. Whit this tool you can make opening files, you can also download your games, analyse them ( you can ask for report and computer will give you your accuracy and it will anotate your moves) and put them all in one (or more) files ( for example I have a file for my blitz games, one for my rapid games and one for all tournament games). And that's not all, you can also practice with 3+milion puzzels. On top of that you can also connect it with your chess.com / lichess.org account and it will show you your win procentage over months and your win-rate with difrent opening. If you want to download or learn more about this free online tool, you can visit this website- https://encroissant.org