Promo Instant Image Resizer - Automatically optimize images for web & social media (free!)
ImageKit.io - Instant multi-platform image optimization
Responsive Image Breakpoint Generator - Turn one image into the ideal set of per-device images
Placid - Use Placid to auto-generate images, videos & PDFs from reusable templates
Promo.com - Every promotion starts with Promo.com.
Webflow Flexbox UI Builder - Build flexible, responsive layouts — without writing code