Another fair point! The truth is, everyone’s ‘high energy’ is a little different. What my period of high energy is could be very different from yours. Its highly personalized hence we would require the user input here, what they think works best for them. Get their feedback on their energy levels through the day (asking them few times a day) and then sort of predict their high-productive hours for them to schedule their most important work during that time. Let me know if this sounds stupid or if it makes some sense.

Ooo very relevant q

For cheap.. Have him share his EEG+CGM RT readings

Midterm outlook (multimodal data fusion/pretraining):

https://www.sciencedirect.com/science/article/abs/pii/S10538...

https://news.ycombinator.com/item?id=44727191

Those are valid points. Here would be my simple approach (tell me if you think it doesn't make sense or needs some adjustments):

Short, occasional check-ins: The app could nudge you (maybe just once in the morning, afternoon, and evening for a week) to rate how you’re feeling, with a tap or two — think 2 seconds, not 2 minutes.

Learn from your habits: After this “trial week,” the app would look for patterns. For example, if you usually feel sharp at 10am, that gets noted. No need to keep checking in all the time.

I imagine you'd have to log and it finds a pattern. Problem is it can be related to factors the app doesnt have data on.

Another potential idea is biometrics I.e. what sports watches do. Not sure if that stuff is voodoo or real tho.

Thats a good idea. Thanks for the feedback.