IndieHacker Teens August 13, 2020

I'm 15 and made a 😴 bedtime calculator with React JS

Josh Ternyak @JoshTernyak

Ever wake up feeling groggy, even though you thought you had enough sleep? It turns out that by timing your wake up time based on REM cycles, you can wake up more refreshed and more productive.

This got me thinking, why don't I put my front-end web development skills to the test and build a tool that will help people, especially Indiehackers who are known for working late at night to know when they should go to bed depending on when they want to wake up?

So, I built a bedtime calculator that calculates when you should wake up based on REM cycles, which on average last 90 minutes.

I would love feedback! @csallen @braydentw @rosiesherry

  1. 2

    Hey Josh, I have some feedback.questions ready for you.

    • Why do you have the sleep calculator on your SleepSources website? It isn't linked on the home page to it so how do you expect someone to find it?
    • Does the content after you get your results help SEO? Why not just make a separate article on your website with the same content? It made me feel bit overwhelmed and I'd rather just see the results and maybe a "share on twitter" button.
    • Since I'm not super great at React (yet 😉), I want to understand why you chose to use React to create it instead of Vanilla JS.
    • Have you thought of adding a dark/light mode toggle?
    • Why did you choose the teals and blues as your accent colors? Why not just stick with Sleepsource's colors (orange, purple, light purple) so it is more recognizable?
    • Have you posted about it on other sources? (Medium,, Freecodecamp, other guest posting sites with high DA)
    • Will you make it open source on Github? I think it would be very popular and a cool open-source React app that developers can contribute to.

    Hope this helps!

  2. 2

    Wow.. impressive work, Josh. I like it. Keep it up! :)

  3. 2

    This is really easy and user-friendly to use!

  4. 2

    Great work, very impressive for being 15!

  5. 2


    I am impressed with the scientific approach, and quality explanation you presented on that page. Also impressed when a young and smart person like you invest his energy to build something useful. Great job!

    I can be potential user for the problem you are trying to solve. I want to get up as much earlier as possible (5:30 AM), and I want an android app that can wake me up when the REM cycle ends.

    You can go to bed but fall asleep later, and the Android app can analyze my body motion with the sensor, and based on that conclude when did I fall asleep. Based on that, and also on how much deep sleep I had, app can calculate perfect time and woke me up.

    That kind of apps exists, but they are not perfect. Some do not even try to predict sleep time, and for sleep time use the time when you started the app, which is incorrect.

    This is the app that has lot of features, but unfortunately, sleep time is not accurate. -

    1. 1

      Thanks so much for the feedback and support! I'll look into building an improved version of that app you talked about :)

  6. 2

    Awesome work Josh! You inspire me to learn Reactjs more :)

    1. 1

      I'm so glad :) Thank you Brayden

  7. 2

    Awesome work Josh. Wish I'd had that amount of drive and vision when I was 15.
    You will go far, I'm sure.

  8. 2

    It’s really nice! The design is so neat and the Web app is quite interesting as well as useful.

    1. 1

      Thank you! That means a lot, I'm glad you find it useful :)

  9. 1

    @JoshTernyak : Kudos, neat & impressive stuff at age of 15!

    If you want to spin up quick backend REST APIs, try - literally 100s of REST APIs within seconds. Would be wonderful to see what young minds can do with it.

    Here is a small demo :

    Happy to help you started over a zoom call :

    Feel free to get in touch.

  10. 1

    This is awesome, keep going, and make new awesome products :)

  11. -6

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