Drupal Themes can be created from existing responsive themes such as Omega and then customise it. Theming is a fantastic Drupal feature to implement any kind of design in terms of responsive structure such as setting up regions with a 12 grids responsive layout, very good for mobile.
Mobile Development
Maria Consulting LTD
Pasquale Laudonio
A web site must be easily accessible using different mobile devices and tablets with different screen resolutions and widths which usually are between 320px up to 800px. The web site must be displayed properly on all these different resolutions. The Bootstrap Theme is a FREE framework that can be used as a Drupal Theme to implement this solution.
Related Services
How to create a Custom Accordion in Drupal 8 using the Paragraphs Module
If you cannot find a module that does exactly what you need then need to write a custom module. First try to find the same functionality in some existing contributed module. Sometimes it is wise to alter or extend an existing module rather then rewriting the functionality from scratch.