Oh, no haha. That would be pretty neat though.

I think you'll come to understand and appreciate it once I implement it. The crux of the app is that it mostly is responsible for tracking data over multiple sleeps, both subjective and objective. As a mere data tracker and interpreter, it doesn't "beat" a wristband monitor, it actually complements them, because they can be paired together, but this is a feature that wont be added until later on.

Depending on the wristband, in my experience, the data isn't always reliable. The Pinetime is much better than it used to be. Some wristbands track more than just pulse even, also tracking oxygen saturation, which is very handy.

Step one is just tracking useful user-provided data points. Step two is respiration tracking via the mic, by far the most useful feature in my opinion. While it's only one metric, and it can be messed with, and the quality isn't always perfect, the amount of inferred data is huge. Step three will be getting the accelerometer going, which I don't think is too useful for me, but it's a highly requested feature. The trick isn't to strap it to yourself, but to let it rest on your bed with you. The phone moves when you do. You may also put it in your pocket, but I don't think I'd recommend that because you'll definitely want to keep it connected to a charger. The (sum of the absolute value of the) little jiggles it'll detect can always be scaled up and down, or weighted differently on a per-user basis. Step four, getting paired hardware online. Step five, (with extra funding), might involve actually researching the hardware and techniques used in sleep analysis, building a type whatever-I-can-afford DIY kit, and optimizing how well the app works overall when working with clinical data/hardware.

One last thing, if you don't already own a smartwatch and cannot afford one but want to track sleep data, but you do own a mobile Linux phone, then it makes far more sense to either track your metrics yourself via pencil and paper, or plug some data into a tracking app.