Mixpanel create this cute login or signup buttons on top of their home page, which links to their seperate login page. The login page then have this blue asterisk mark denoting that the field box is required to be filled up.
Application Craft’s login screen is a simple login which uses email & password to login. it has Remember Me feature and it also supports multi-language. A small text noting the version number and the date of the login application was built.