Plenty of people use their smartphones for basic calculations. Graphing calculators could still prove useful to scientists, students, and professionals. Take the TI-Nspire CX II Graphing Calculator for instance: it is a powerful calculator with a color, backlit display, 320 x 240 pixels resolution, and improving coding and math features.
You will be able to enter equations, graph data, construct geometric shapes, and enter notes/instructions. You can also write code to visualize math, science, and STEM ideas.