What are some alternatives?
When comparing WP Smush and TinyPNG, you can also consider the following products
Yoast Plugins - Yoast offers plugins to improve SEO and optimize web sites and blogs.
ImageOptim - Faster web pages and apps.
pngquant - command-line utility and library for lossy compression of PNG images
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.
PNGGauntlet - -Combines PNGOUT, OptiPNG, and DeflOpt to create the smallest PNGs
Wordfence - Comprehensive security plugin for WordPress.