Downloading SearchPubChem 4.2 for Mac from the developer's website was possible when we last checked. We cannot confirm if there is a free download of this app available. We recommend checking the downloaded files with any free antivirus. The software lies within Education Tools, more precisely Science. The actual developer of this free Mac application is Jae-Seung Lee.
From the developer:
Search PubChem allows you to search compounds through ‘PubChem’ and helps you to keep information on solutions made of those compounds. The tool lets you search the open chemistry database 'PubChem' at the National Institutes of Health for chemical compounds. The app helps you to find a compound in a collection of more than 111 million compounds. It downloads and stores the molecular formula, weight, and structure.
You may want to check out more software for Mac, such as Gee, Arcade Math Blocks or NLVM, which might be similar to SearchPubChem.