After three years and 2,000 hours of development, I finally added a paid tier to FluxTime. Honestly, the main reason I chose this moment is fear, not confidence: I am afraid that once I turn on payments, almost no one will use the app, and everything so far will have been for nothing. The more time I have put in, the larger the sunk cost, and the stronger that fear becomes.

By the current mainstream advice, this is a bad time to start charging. Most software now puts up a paywall from day one to validate the idea: if people pay, the idea is right; if they don't, you quit and try the next one. FluxTime is not software whose effect shows up in a day or two. Time tracking itself takes at least a few months before it really changes how someone perceives time. If I had put up a paywall at the start, what I would have been testing is not "is this idea right," but "will I pay for something whose effect I have not felt yet." Those are two different questions.

Over these three years FluxTime did have one brief spike, with nearly 1,000 new users arriving at once, and retention was extremely low. People did not stay largely because the product was unfinished, buggy, and hard to use. That is a product problem, and it is not the same thing as "the value takes time to show." That is also why I did not turn on payments then: if the product is not ready, charging early only distorts the test. Today it is an app with about 150 monthly active users. It is not a hit. But it is a version I use every day, and one I am finally willing to put in front of people. That is why this finally feels like the right time.

What kept me building it is the conviction that this is good for people, and that conviction comes from understanding: from 2024, recording time every day until the recording became intuition, I actually felt that my sense of time had changed.

Knowing and understanding are not the same thing. Everyone knows that time is precious. Most people do not understand it. Most people know that a large sample gives more precise statistics than a small one, but few understand why: small samples produce more extreme results, which is exactly why large samples are more reliable. The first sentence (large samples are more precise) is explained by the second (small samples go to extremes). Only when the second sentence becomes intuition do you actually understand the first. If you only "know" the conclusion, your intuition will still fool you.

There is a report of a kidney-cancer survey across 3,143 U.S. counties. The striking finding: counties with low kidney-cancer rates were often sparsely populated, Republican-leaning rural counties in the South and Southwest. It is easy to infer that clean air, less pollution, clean water, and natural food explain the lower rates. In fact, the counties with high kidney-cancer rates were also sparsely populated rural counties. The reason is simple: a small population is a small sample, so extremes show up more easily, whether high or low.

Time is the same. Everyone "knows" time is precious. Only when you record and look at your own time, day after day, the way you would look at a sample, does "was this time enlarged or wasted" stop being an abstract conclusion and become intuition in your body. That is the difference between understanding and knowing.

Time is the most basic means of production

Most people treat money as a resource and never treat time as one. Wasting 100 yuan hurts. Spending hours in line for a discount, or for a new milk-tea shop, does not. Time is more basic than money. It is the most primitive resource: food, skill, income, even relationships. Anything you get, you first put time into.

In a hunter-gatherer world, people spent time learning to hunt and forage, then traded those skills for food and survival. Whoever was more skilled got more back in the same time. Modern life has not changed that structure. The chain is longer and the forms are more complicated: we spend time learning, trade that for a diploma, sell our time to a company, the company turns resources and demand into products, products into money, money into wages. The chain got longer. The starting point is still the time you put in.

Time is a pipe

Most people still think of time as a line: life from birth to death, a two-dimensional ray. Time is closer to a three-dimensional pipe. It has a cross-section, and it has volume. Think about your own life: a stretch of intense effort (the last year of high school), and a stretch that felt loose (a relatively idle university). That is thickness. High school was a thicker pipe; university was thinner. Multiply the cross-section by length (three years of high school, four of university) and the volume of time is completely different. The same "one year" can differ several times over.

That is why people describe skill in years: "I have played guitar for six years." That is line-thinking applied to a pipe: it records length, not thickness. Two people can both say six years and have completely different volumes. One takes a two-hour lesson once a week: 624 hours in six years. The other practices two hours a day: 4,380 hours in six years. The second person's first year already exceeds the first person's six years. Both CVs still say "six years of guitar."

Pilots are a better reference. Their records are not "X years of flying." They break hours down by role, aircraft, environment, and mission. Flight hours are experience and qualification. Vague years mean nothing. Volume is what counts. That is what I have been thinking about with FluxTime: if you really want to know how much you have put into something, you do not need a timeline. You need a log like a flight log: not only how long, but on what kind of work, and how thick the volume became.

Time is the basis of compound interest

Most people only understand compound interest as money. Almost every good thing in life is compound interest on time: skill, body, wealth, relationships. Compound interest is iteration: you work on top of what you already made, and the next pass sits on this one.

Whether the next pass can use the last one is the difference between investing time and consuming it. Short videos, games, shows leave nothing the next session can build on. Each time starts from zero, so nothing compounds. Real time investment is often dull and slow to show, but it is laying the next layer. That is also the difference in feedback: consumption pays dopamine immediately; investment often waits a long time before the curve is visible.

The biggest change this understanding made for me is that I dropped time-consuming activities and moved toward investing time, not by forcing myself off my phone, but because I can see that compound curve in my head, and I know the dullness will turn into return. People move toward reward and away from pain. Everyone knows games and short videos are not good habits, and still cannot stop. That is not a willpower problem. It is knowing versus understanding. Recording time is the method I found for turning knowing into understanding.

The judgment stays with you

This is the answer to the opening question: why charge now. Not because I finally feel sure. Because every stretch of time recorded over these three years is itself the evidence in this piece: time is not a line, it is pipes with thickness that can compound, and FluxTime from day one was built to help you see that. Not to pack your calendar fuller, but to show which goals your time went into, and how much. It does not decide which goals deserve your time. You define the categories, because an app should not decide that for you. The judgment should stay with you. That judgment is understanding.

As for the fear I started with: some people will leave. That is normal. Something that takes months to show should not expect everyone to wait. The people who stay will be the ones who actually understand it. And that may be the users FluxTime has been looking for all along.

Also published on WeChat. FluxTime is free to download, Pro optional: fluxtime.io