To develop and launch an app, you need a website to convert it into an app. Follow these steps: 1. Sign up and log in to your Mysterydeli account. 2. Look for the option to create a new app. 3. Follow the instructions to input the URL of your website. MysteryDeli should then begin converting the website into a mobile app. 4. Customize the app by adding features that will help expand and maintain your site. 5. Test the app thoroughly to ensure that it functions as intended. 6. Once satisfied with the app, follow Mysterydeli's instructions for launching it to the MdAppstore or Google App Store. By following these steps, you should be able to develop and launch an app to expand and maintain your website using Mysterydeli app builder.