You may think Einstein’s theories have nothing to do with you, but without them your mobile phone would not be able to tell you your location
The satellites of the Global Positioning System, on which smartphones and satnav rely to determine location, move in highly elongated elliptical orbits around Earth. When each swings in to its closest point to the planet, it experiences stronger gravity and its on-board clock slows down; when it recedes to its farthest point from the planet, the clock speeds up. This is according to Einstein’s general theory of relativity. However, an effect of Einstein’s special theory of relativity causes the clocks to slow down when they are moving fastest. Both of these effects must be taken into consideration by the software that, unbeknownst to you, calculates your exact location on the Earth’s surface.
Satellites in orbit also have to compensate for gravitational effects to work properly