We designed this plugin to meet basic needs of a developer who would like to have a limited access to his site while providing quick fixes. As a result we made a user friendly splash page with comfortable back end, that allows to manage settings without interfering with the code.
The main challenge was to build a mechanism for authentication and validation. We created it so that users stay on the same page when they input wrong initials. The rest of maintenance plugins redirect users to wp-login.php page.