General online utilities in my opinion are great for passive income. They usually require only a small amount of work in first instance and little to no maintenance going forward.
I do imagine these to be low in reward although the demand for them should be infinite and evergreen. I have decided to begin with a simple password generator online, that at a click of a button presents a 16 character password – ever creating an account somewhere and the only password you can think of is ‘password123’? Think we have all been there at some point.
The site in itself only took a few minutes to get set up, there are an unbelievable amount of PHP projects online for password generation which is what I have done. The front-end HTML simply calls the PHP function each time the button is clicked and presents the user with a newly generated password.
If you’re interested in the source code being published for the project let me know.