How do I change my BandHelper password in the PC app?
I'm not sure what you mean by "PC app." In the website, you can go to the Account > Users page. In the mobile apps, you can go to the Settings > General Settings page. Note that changing it on the website actually changes what is saved in your account, while changing it in the apps only changes what you are logging in with. So to actually change what your password is, you will need to change it on the website, then enter the same password into all your apps so they can log in with the new password.