Nestor 1.0 for Mac was available to download from the developer's website when we last checked. We cannot confirm if there is a free download of this app available. According to the results of the Google Safe Browsing check, the developer's site is safe. Despite this, we recommend checking the downloaded files with any free antivirus software. The program is included in Productivity Tools.
From the developer:
Nestor offers a free Google Chrome extension to automatically highlight the important sentences on your favorite sites, helping you scan an article for the relevant information. The product uses advanced Natural Language Processing and Machine Learning technologies to identify the sentences with the most relevant content so you can quickly grasp the information you're looking for.
You may want to check out more Mac applications, such as Nesting, MyNest or SSPX, which might be similar to Nestor.