tinyPNG.App is described as 'provides a GUI front end for tinyPNG for your local computer so you can optimize images using the tinyPNG API service. Available on Windows, macOS & Linux' and is a Image Optimizer in the Photos & Graphics category. There are more than 50 alternatives to tinyPNG.App for a variety of platforms, including Windows, Online / Web-based, Mac, Linux and Wordpress. The best alternative is RIOT - Radical Image Optimization Tool, which is free. Other great apps like tinyPNG.App are ImageOptim (Free Personal, Open Source), XnConvert (Free Personal), TinyPNG (Freemium) and Statically (Free, Open Source).
Saving images for web/email/other media with the best compression ratio and quality is a difficult task if you don’t have the right tools. Choosing the right format then choosing the right parameters are the key factors of smaller files.
ImageOptim is excellent for publishing images on the web (easily shrinks images “Saved for Web” in Photoshop). It's useful for making Mac and iPhone/iPad applications smaller (if you configure Xcode to allow better optimization).
XnConvert is an easy image converter for graphic files, photos and images available on Windows, MacOSX and Linux. It supports more than 400 file formats (jpeg, tiff, png, gif, camera raw, jpeg2000, WebP, OpenEXR, ...).
Experimental, fast Web PNG/JPG optimizer which offer lossless, visually lossless or lossy compression. it performs image reductions over iterations thanks to recursive multi-processing and multithreading systems.