Here are the tools I use (or tried) when creating, optimizing and animating SVG files. The list is certainly not exhaustive, the web contains tons of essential tools dealing with SVG.

SVG creation

• Inskcape
• Gravit Designer
• Janvas
• Vecteezy
• Boxy

SVG optimization/cleanup

• SVGOMG
• SVG Path Visualizer
• Vecta.io

Convert to SVG

• PicSVG

SVG Encoder

• URL-encoder

SVG Filters

• SVG Filters
• SVG Gradient Map Filter

SVG Animations

• SVGator
• Loading.io
• Shape Shifter
• SVG Artista

SVG libraries

• Snap
• SVG.js
• Two.js
• GSAP from Greensock