That “other app” offering was released using the older GSAP 2 (not v3) and ScrollMagic. GSAP has since released their own ScrollTrigger so ScrollMagic is a thing of the past and way less capable comparatively to the new native approach now offered by GreenSock.
Both GSAP 3 and ScrollTrigger are far better than what is presently found in that “other app” and so far they have yet to update things in their app. What that “other app” outputs into the source code is rather unmaintainable data-attr’s as cryptic animation data that their own custom library powered by GSAP uses to animate things. Which means its not that transferable within a larger development cycle without that specific “other app” to edit things unfortunately.
However it is a pretty nice GUI and you can do a lot with it based upon imagination given its features without the need of knowing code. But like all it certainly has limits like I mentioned in this other thread. This “other app” and other various tools have successfully allowed an albeit limited visual approach to various specific aspects of GreenSock without the requirement of hand coding.
After that “other app” released their GSAP related offering, Blocs released the HYPE integration (see the documentation) which was a long time coming but is finally here. So I would be quite suprised if Blocs visually integrates GSAP directly anytime soon (if ever) since it would be a huge undertaking. 