Many companies use this software for editing photos.
I use this for our company work and this works perfectly for image editing process.
GIMP - GIMP is a multiplatform photo manipulation tool.
UI Garage - Specific mobile and web design patterns for your inspiration
Affinity Photo - Affinity is the imaging and design suite for creative professionals exclusively for Mac.
Muzli - UI/UX and Design Inspiration Chrome Extension
Krita - Krita is a professional FREE and open source painting program. It is made by artists that want to seaffordable art tools for everyone. Concept art. texture and matte painters, illustrations and comics.
Design Hunt - Curated design inspiration for everyone