A lot depends on what someone is looking for. Do they care about scheduling classic posts or scheduling carousel posts?
Not many people know that you can post many different post formats on Facebook with many different CTA buttons.
I recommend SoMe Planner because it has the ability to schedule carousels, posts with a link and any graphics, and canvas posts (instant experience). In addition, it analyzes and suggests at what times to publish.
It may not be very popular, but it works great and is inexpensive.