DEVONagent Lite
If you do much research in your browser, and you're past the stage where you just use Google everything, DEVONagent Lite gives you keyboard quick access to seventeen different categories of reference material, most of them with multiple sources to choose from. No longer do you need to find your browser bookmark for the website you want to use for search. You type your query right in the menu bar of macOS, choose the category and site you would like to search, and press enter. The resulting page opens in your default browser.
The search categories and some of the most useful sites are:
Search - Google, Brave, Bing, Yahoo, DuckDuckGo
Apple - App Store, Knowledge Base, Mac Update
Blogs
Computer Science - GitHub, StackOverflow
Dictionaries - Onelook, Wiktionary, Info Please
Directories - Open Directory, WoW, Yahoo Directory
Discussion Lists - Yahoo Answers
Government - USA.gov, Firstgov.gov
Images & Videos - Google Video, Picsearch, YouTube
Legal - Google Scholar, FindLaw
Medical - FDA, HeathFinder, PubMed, WebMD
News - BBC, Google News, Reuters
Patents - US Patent Office, Google Patents
References - British Library, Gutenburg.org, Wikipedia
Science
Shopping - Amazon
Social Networking - Facebook Profiles
You cannot add or remove search sites in the free version, nor can you directly access any type of AI. DEVON offers an express version of the app with a few more features for $4.99 and a pro version for $49.99. You can check out the features for each version at the DEVON web site.