Based on the user reviews of the "Drink Stack" app, here are three cons and pros in 15 words or less each: **Cons:** 1. "Limited functionality" - Some users find the app's features restricted compared to other apps. 2. "Clunky design" - The user interface is criticized for being unappealing and difficult to navigate. 3. "Inaccurate tallies" - Some users report errors in counting their daily water intake. **Pros:** 1. "Simple and easy to use" - Many users appreciate the app's straightforward design and intuitive interface. 2. "Customizable reminders" - Users praise the app's ability to set personalized reminders for drinking water. 3. "Helpful tracking" - The app's tracking feature is commended for helping users stay on top of their hydration goals. Please note that conclusions are subjective and based on a snapshot of user reviews at a particular time.