uPic 1.8.4 for Mac could be downloaded from the developer's website when we last checked. We cannot confirm if there is a free download of this app available. This free Mac application was originally produced by uPic. UPic for Mac lies within Design & Photo Tools, more precisely Viewers & Editors. We recommend checking the downloaded files with any free antivirus.
From the developer:
uPic is a powerful image lossless compression software app. It introduces the compression algorithm of TinyPNG API, provides "lossless" compression service for PNG images, and reduces file size by 60%-90%. The compressed image may only be the original 1/8 size, but the quality is flawless.
You may want to check out more Mac applications, such as PulpMotion Advanced, I Can Animate or PDF Studio, which might be related to uPic.