Please note: This is not a password manager!
Most people use a single password on every account they have, and it is usually a bad one (too common, too simple and too short). Stop using “123456” and “password”!
Password managers are great (and I encourage you to use one), but there are instances where the device you are using can’t (or shouldn’t) have one installed and/or have harder input methods (a router, public/shared computer, an IOT device, etc). On these occasions, you shouldn’t sacrifice security.
The passwords that this App generates are relatively easy to remember and to type, and are a lot better and safer than the ones a human can come up with.
I use the Diceware™ concept, but instead of using a physical dice, I use a cryptographically secure offline random number generator (the one included in your devices OS) to "roll the numbers".