I think being able to mask and unmask your password with a checkbox is certainly viable(as long as the masking is the default). The problem lies not with users like you who have different passwords for different applications, the problem lies with users who have the same password for all applications.
That being said, that is probably beyond the scope of what the author is trying to address but is still always something to consider.
That being said, that is probably beyond the scope of what the author is trying to address but is still always something to consider.