Same here — sometimes I just need to send one quick document. I found a few good options through
master-league.com. They include a list of Android fax apps that allow “guest” or one-time use without registration. I tested one of them, and it worked perfectly — sent my file straight from my phone without making an account. It’s ideal for one-off needs. If you value privacy and simplicity, I’d definitely look at their quick-send app recommendations.