Distance teaching and learning due to the Covid-19 pandemic was perceived as a major challenge by both, teachers and students. Emerged ways of instructionsummarized in the term Emergency Remote Teaching (ERT)could not fully meet the needs of online teaching and learning in Spring 2020. With a particular focus on reported challenges of mathematics distance education, this paper firstly aims at providing a theoretical framework for the development of mobile environments for distance math class. In doing so, we refer to the Community of Inquiry (CoI) model, e-pedagogy, and mobile learning to deduce design requirements. Secondly, the ASYMPTOTE project is introduced as an example for mobile mathematics education at a distance. Based on the discussed Covid-19 experiences and the derived design requirements, the present status of the ASYMPTOTE system is evaluated. In addition, necessary further developments of the system are identified.