I had downloaded about three or four before finding one made by someone named Adam Cziko.
The Cziko one works best for me, because there are (for now) seemingly unlimited symptoms and treatment slots. Plus, you get to write in your own terms vs. choosing from a list.
I have some weird symptom, so I really did not like that some of the other apps tried to fit my weird symptoms into a neat little rigid box. And/Or limited the number of symptoms I can list. Because I got lots.
My only worry about the Adam Cziko app is that it tells me to upload to premium for unlimited symptoms and treatments. I'm open to uploading to premium. But when I click on upgrade to Premium, I get this: