What are some alternatives?
When comparing Imagify.co and TinyPNG, you can also consider the following products
WP Smush - Reduce image file sizes, improve performance and boost your SEO using the free WPMU DEV WordPress...
ImageOptim - Faster web pages and apps.
Gravity Forms - Gravity Forms is one of the best and easiest contact form plugins to create modern forms for websites powered by widely-used WordPress.
pngquant - command-line utility and library for lossy compression of PNG images
Bitfinex - Bitfinex is the largest and most advanced crypto-currencies trading platform.
PNGGauntlet - -Combines PNGOUT, OptiPNG, and DeflOpt to create the smallest PNGs