Have you made video tutorials? If people could see how it worked and how to use it, I bet it would be a lot more compelling. Start a YouTube channel for it, and have a video on the main page (not autoplay, though).
There is a saturation of dev tools available both licensed and free. It is difficult to separate yourself from the pack. The sad truth is there are no cheap, easy and effective ways to promote a product. The only way to get your name out there is hard work or deep pockets.