I like summarygenerator.io since it can store all my previous summaries.
Resoomer - Resoomer is a software and online tool for text summary: it allows you to summarize and analyze your articles by taking up the important concepts
Blinkist - Key insights from 6,000+ bestselling books and podcasts
summary.com - Read, Watch, Listen, Learn
Instaread - Read or hear key takeaways of any book in minutes
Dovetail - Mobile Cloud-Based Dental Software
wits.io - Weekly book summaries recommended by founders and makers