I personally use a spreadsheet but I'm sure there are better way to do it.
Do you know any good websites/apps to do it?
I think you not needed a spreadsheet or anything else because in trading yes we make profit and losses but it is more on winning or profit if you use to trade well or lets we say that you have a good skills in trading we doesn't need it anymore it will just ruin your trade by being greedy if you lose more than profit in some circumstances.
I haven't think about it by yes for starters a spreadsheet would be a good thing to used for tracking your win/loss record. However, right now I haven't used any because I don't take profit but instead try to roll my money on investing or just simple don't trade if I don't feel like to. But its a good thing that you brought this idea. I don't know if there is a software out there that can you get to automatically jot this information for you. If there is one, it would be a great tool for us traders.
Its good but as long as you enjoying trade you will won't recognize it and all you wanted is to trade. Honestly i don't use any to record i knkw what amounts i lost not all but i can compute the nearest amount and i just based on my buying and selling history per coins. actually for all exchange i registered i have more than 100 coins so how is it and it will be a time consuming if i will record it all.p