The phrase identifies software applications designed for creating technical drawings on Android operating systems without incurring any cost. These applications typically enable users to generate 2D and 3D models, technical diagrams, and architectural plans directly on their mobile devices. An example includes a program allowing architects to design a building blueprint on a tablet at a construction site, bypassing the need for a desktop workstation.
Accessibility, portability, and cost savings are key advantages. The availability of such tools democratizes design and engineering processes, providing students, hobbyists, and professionals with on-the-go capabilities. Historically, CAD was limited to expensive desktop workstations, however, the proliferation of mobile devices and advancements in software development have made these resources more widely available.