Dear Sir, I am a full stack developer with android experience. The application you are asking for is very simple and can be delivered in one day. I have asked for 2 days to allow for testing and feedback on your end.
The application shall have 2 pages: the main page for email subscriptions with 3 text input fields name lastname and email
1 button to open settings, and the settings page (password protected with the possibility to reset the password if forgotten) which shall have the following fields: background image select, background image remove button, background color select (willy apply if no image is selected), background tile or strech checkboxes, text inputs api key, list id for mailchimp, admin user email, admin password (with confirm field) and a save settings button (optional)
Should you be interested in awarding me the project please contact me via chat to finalize the requirements and start the work.
Best Regards, Alain