As a UX/UI designer I use a variety of tools. Different jobs ask for different tools.

#1. Sketch
Perfect for designing digital products. With the different plugins you can adjust it to your own usage.

#2. Adobe XD
Kind of a similar of Sketch. But the difference is that adobe XD has a perfect prototype module within the app. No need for downloading external plugins. Another benefit is, it works great together with the other Adobe creative cloud tools.

#3. Invision
Great prototype tool. Easy to upload online, link the screens and share with clients. Great in combination with Sketch.

#4. Illustrator
A classic, but still the best tool for designing icons.

#5. Omnigraffle
A perfect tool to setup up complex flowcharts.