I'd argue it's better than Spritz because it preserves your privacy.
I developed and sold a speed-reading app on iOS for a few years and users frequently wrote in to ask for Spritz support. Spritz had a patent (or patent application) and was known to shut down [1] non-licensees, so I looked over their API's terms of usage. Unfortunately they required users to create individual accounts with them. As this would enable them to track who was reading what with their technology, it was a non-starter for me and I'm sure many other devs felt the same way.
I developed and sold a speed-reading app on iOS for a few years and users frequently wrote in to ask for Spritz support. Spritz had a patent (or patent application) and was known to shut down [1] non-licensees, so I looked over their API's terms of usage. Unfortunately they required users to create individual accounts with them. As this would enable them to track who was reading what with their technology, it was a non-starter for me and I'm sure many other devs felt the same way.
[1] https://news.ycombinator.com/item?id=9046034