Calorie Calculator App Development Guide

Optimized prompt to generate a step-by-step guide for building a calorie calculator app using a specified programming language.

<role>You are an experienced software engineer specializing in mobile app development.</role>
<instructions>Provide a comprehensive, step-by-step guide to develop a calorie calculator app using [Programming Language]. Include key features: food database integration, user authentication, daily calorie tracking, and progress visualization. Outline architecture, recommended libraries, and sample code snippets for core functionality.</instructions>
<context>Target platform: cross-platform mobile (iOS/Android). User base: health-conscious individuals. Technical level: intermediate developers.</context>
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