Hey Luis! Seeing all these other thoughtful comments I felt like I should do better.

I think the new-user flow is the most important thing that's lacking right now. Signing up was easy (but see minor bug report below). But then I'm greeted with a blank page.

What I think I should see instead: some sort of "welcome wizard", explaining the next step and encouraging me to choose a study. I'd suggest something like: large attractive tiles, one for each existing experiment, plus an "or design your own" tile. Clicking one of them should take me to the new experiment flow, either pre-filled or not.

The new experiment flow itself could use a bit of work. The fields are only labeled by placeholders (generally bad practice), and probably could use more explanation. E.g., let's say I want to create a modafinil-for-energy study. Where do I even put the text "Modafinil"? Maybe that's the "Experiment Name"?? What's the difference between "Energy" and "Focus"? I think you could expand this into something much more detailed, with e.g. a sentence or so explaining each field.

After I create a new experiment, I'm dumped back onto the empty dashboard. (With the experiments sidebar still collapsed!) I think instead I should be sent to that experiment's page.

Stepping back a bit, I really like the pages you've put together for preexisting experiments. (Alpha-GPC, L-Tyrosine, Binaural Beats, L-Theanine.) However, they are hard to get to (two-level dropdown menus are annoying to use! There should just be a landing page listing them all, maybe with headings and summaries!). And I don't think they're connected enough to the rest of the site. I think centering more of the design around those would make a stronger tool. E.g., displaying some of the info from the protocol in the experiment's data page would be good. And adding a bunch more, even if you start out with placeholders for "State of the Evidence" / "Toxicity" / etc.

Also, after being logged in, I navigated through the dropdown menu and went to https://n1.tools/experiments/anxiety/lTheanine and clicked "Start Experiment". The first time I did this, it took me back to the blank dashboard page, with no new experiment in the sidebar. The second time, it seems to have logged me out and taken me to the n1.tools homepage. Not good! I have no idea how I was supposed to use that page to start a L-Theanine experiment.

A final piece of high-level feedback: beyond just the first-run experience, the blank dashboard is a very bad experience. On first-run, when the user has no experiments, it should have some sort of "get started" wizard like I mentioned above. But otherwise, it should be displaying ongoing experiment summaries or something like that.

Other minor bug reports and suggestions:

• Generally, consider using radio buttons more than dropdowns.

• The dropdowns look grayed out, in the sense that they are disabled and not able to be interacted with (Windows, Firefox). Image. I guess instead this is just a styling choice, but it probably could be better!

• The sign-up flow did not play well with 1Password somehow. I wasn't invited to autofill my email, or generate a new password, and after I entered them, 1Password did not invite me to save the login. (I also got an ugly "Login successful" alert(); I think just sending me to the dashboard would be better.)

• There's no way to view or modify the parameters of my experiment after creating one, if I made a mistake. (E.g., let's say I thought my Modafinil pills were 200 mg, but actually they're 100 mg. I can't even see what dosage I entered, much less change it.)

• It's confusing that "Skipped/Took Placebo" zeroed out dosage. Maybe it'd be less confusing if it made the dosage field disappear or turn into "N/A" text.

• It's modern convention that if you're logged in, you should never see the landing page. E.g. clicking the logo, or going to n1.tools, should send you to the dashboard.

• There's no reason why the "Experiments" in the sidebar should ever be collapsed. (Or why there's even an "Experiments" heading at all.) There's nothing else that could take up sidebar space!

I hope this is helpful, and not overwhelming! Ultimately, the problem is that every project benefits from an engineer/designer/product manager trio, and you're trying to do all three. A PM would be able to guide you toward good first-run experiences, daily flows, what kind of screens your app should have, etc. A designer would be able to make those all delightful to use, without any UX rough edges. But those are hard skills to acquire! I've managed to get some through osmosis by working with PMs and designers for years, but I prefer when possible to leave product and design work to professionals. But you've made a lot more progress than me on all of my single-engineer projects, so I hope you keep at it!!

The website doesn't actually say this, but It looks like this is only suitable for treatments that kick in and wear off in a day. That's fairly easy to do on your own, so the UI would need to be absolutely amazing to entice people. For people who aren't already running their own experiments it needs to feel apple-product shiny and easy. For people who are, it needs to be extremely clear what the product does and how to configure it exactly to their liking, while still being easier than the spread sheet they are used to.

I personally am much more interested in a tool that helps with longer-term experiments. I talk about those kinds of interventions on my blog a lot and there's a reasonable chance I could get a group together to try something if the fit were good.

Immediate onboarding feedback:
- My immediate impression of the homepage is pretty good. There are some nice charts that I don't entirely understand but I assume will be explained later. I am interested in finding ways to measurably improve my life and I assume this will give me some ideas and ways to objectively measure them.
- When I scroll down and click on any of the "three simple steps" I'm just shunted to the top of the page, hope there wasn't anything there I needed to see.
- Clicking the big call to action button does nothing, that's frustrating. I have to go find the register button in the top right. And now it says "registration successful" but I'm still on the homepage.
- I hit the dashboard link and now I'm on a mostly-blank screen. Couple probably use some sort of getting-started dialog. Maybe give a few popular prebuilt experiments that I could start with one click?
- I hit add experiment and it pops up with a dialog with a bunch of fields. I still don't have any idea of what I want to do with this site so I don't have anything to enter here. Maybe give a few ideas?
- Clicking through the rest of the site I see four suggested experiments. Three look like drugs/supplements of some kind which I'm not interested in. The last is binaural beats which is interesting but I don't have time for right now.

I registered, but after thinking more about it, didn't use it. The primary idea I had was to see if caffeine made me more productive. But it seemed to me like doing all of that tracking day after day would be more trouble than it was worth, and a better approach would just be to correlate coffee purchases on my credit card statement to my Github commits per day graph or something.

I think that the primary thing that would make me more likely to use the app would be the ability to onboard data easily. The apple watch idea is interesting. Still, I don't really know if any app is going to be a better choice for me than just writing the code myself to track what I specifically want, and I definitely think that any app that requires me to record an action every day is a non-starter.

I think the name "N of 1" sounds kind of math-y or scientific, when it sounds like it could appeal to a wider audience, who might be turned off by the name.

The red "register from the navbar" button is clickable and looks like the first thing you should click, but it doesn't do anything.

I think the first graph you show should be clear what it's testing. Like the graph could say it's showing the correlation of going on walks with productivity or something.

I’m going to add an update to this since I’ve added a bunch of stuff based on the feedback here:

• Homepage/experiment overview/specific experiment pages have been totally redesigned and everything should be fully functional.

• I’ve added a tutorial that appears the first time a user accesses the dashboard.

• When adding an experiment from the Dashboard, a wizard is displayed to explain the process, as opposed to a hard-to-interpret form.

• This wizard is automatically populated with relevant information when adding an experiment from a specific experiment page.

• When there are no experiments, there is now a greyed out sample dashboard.

• When a new experiment is added, there are placeholders where data will be displayed.

• The dashboard also shows an overview of the experiment (intervention, dosage, scale used).

• The form to add daily data has been redesigned.
  

There’s still stuff I need to add or change, including:

• Making general improvements to the Dashboard UI and UX.

• The navbar on mobile devices (and general responsive design)

• “How it works” hasn’t been touched yet.

• Adding clarification that the current implementation only works for supplements/activities that take effect and wear off within a day.
  

Additionally, there are features I'd like to implement next:

• Tests like n-back or Stroop to measure aspects of attention or focus.

• Integration of wearable data.

• Many more.

Some relevant images below:

Handed out the rest of the bounty to previous answers, thanks all :)

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