Yes, I would like to stress out that it's VERY likely that there are competitors. I believe nearly everything has been already created, and the idea of finding a niche market doesn't necessarily mean to innovate and do something nobody ever ever did, but it's more about offering another perspective of it -> simplification? Modern UI? Same business problem but different solution?
We're almost 8 billion people. If even just a half/quarter of them has a phone or a computer, you can't not find 100 freaking human beings that like what you built.
I am proudly building something in my free time that was probably made over and over, but always without something that I need. Or I have ideas on how such apps could improve, and I have the skill to do it myself, so... Plus the pleasure of learning new things in your free time, why not. Worst case scenario, you can still use your own app.