There are many online tools that designers use. Some people use Adobe XD, InvisionStudio, Figma, and Sketch. Sketch is an easy to use digital design tool that was voted the top designer tool in 2019 through a survey done by uxtools.co. Many sites that you use very often were created using sketch. Some examples are Facebook, Nintendo, Apple, and the ever-popular, Google. This tool can be very useful to all designers and is popular among them. I enjoy creating things using Adobe Photoshop and I think this is another tool that makes designing easy and fun.
To learn about or download for yourself, click on this link. https://www.sketch.com/
To read more statistics on Sketch and other design tools, follow this link. https://uxtools.co/survey-2019/?ref=webdesignernews.com