Trimage is described as 'cross-platform GUI and command-line interface to optimize image files via optipng, advpng and jpegoptim, depending on the filetype. All image files are losslessy compressed on the highest available compression levels' and is an app in the Photos & Graphics category. There are more than 10 alternatives to Trimage for a variety of platforms, including Windows, Mac, Linux, Online / Web-based and Google Chrome. The best alternative is RIOT - Radical Image Optimization Tool, which is free. Other great apps like Trimage are ImageOptim (Free Personal, Open Source), PNGGauntlet (Free), pngquant (Free, Open Source) and JPEGmini (Paid).
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).
OptiPNG is a command-line PNG optimizer that recompresses image files to a smaller size, without losing any information. This program also converts external formats (BMP, GIF, PNM and TIFF) to optimized PNG, and performs PNG integrity checks and corrections.
PngOptimizer compresses graphics files and removes extra, unnecessary data without affecting quality. It will update PNG files or converting BMP, GIF or TGA files to the PNG format using simple drag-and-drop.
With Image Optimizer you can losslessly optimize your PNG, JPEG and GIF files and thus save your bandwidth and your users' time! Kraken recompresses images with blazing speed and strips metadata with image quality intact.
TruePNG is one of the most advanced PNG optimizers available. It does the most exhaustive checks for reductions, that lets it to optimize further, even if it uses a less efficient compression algorithm than others tools.