Challang
HYDRATION AQUARIUM
A playful daily hydration app where drink logs fill a living water-cup aquarium while caffeine, alcohol, and recent history shape the recommendation.
Most hydration trackers treat the habit as plain water volume. Real users drink coffee, tea, milk, soda, alcohol, smoothies, and custom drinks, so the product had to stay quick while still explaining how each drink affects recognized hydration.
I shaped Challang around a structured beverage database, fast drink recording, recognized hydration calculation, aquarium feedback, daily history, weekly insights, reminders, Firebase sync, and optional Apple Health / Health Connect export.
The app turns a repetitive health utility into a living feedback loop: the user records a drink, sees the water level rise, notices caffeine or alcohol context, and returns later to understand the pattern.
Water-Cup Home
Challang keeps the basic action simple: record what you drank. The product value appears after that moment, when the app turns a raw drink into recognized hydration, raises the water, and lets the aquarium react.
1,890 / 2,200ml recognized hydration
Drink Engine
The app records consumed volume, then applies a beverage-specific hydration factor and keeps caffeine or alcohol as separate context. That is the difference between a cute tracker and a usable wellness product.
recognizedHydrationMl = consumedMl * netHydrationFactor
Contextual Feedback
When coffee stacks up, the app can surface caffeine state and let coffee objects drift in the aquarium. Alcohol is not treated as hydration progress; it becomes a separate caution signal that changes the mood of the water.
Coffee does not disappear into a water total. It stays visible against the daily reference line.
Alcohol is converted into grams and standard drinks, then handled as caution context.
Previous day and weekly records shape the next recommendation instead of resetting the story.
Habit Loop
Today sheets, calendar review, weekly average, caffeine and alcohol panels, reminders, sync, and health export keep the experience useful after the visual reward.
Quick-add, category, search, amount preset, custom amount.
Hydration factor, caffeine, alcohol, sugar, local day key.
Water level rises, fish appear, coffee or wine context surfaces.
Today sheet, calendar, weekly insight, reminders, health export.
