This update makes learning Excel more structured, practical, and reliable. • Expanded the course to 10 progressive lessons, covering formula fundamentals, cell references, logical formulas, conditional math, lookups, text cleanup, data organization, error diagnosis, analysis workflows, and auditable workbook design. • Added 26 quiz questions across references, formulas, tables, formatting, sorting, data validation, charts, PivotTables, dynamic arrays, shortcuts, and more. • Added 8 guided practice exercises with realistic datasets, helpful hints, and formula validation. • Every supported function now includes a worked example, expected result, and clear explanation. • Improved the Formula Playground with nested-function support, absolute references such as $A$1, more accurate decimal results, and corrected rounding behavior. • Fixed learning progress so completed lesson steps remain saved between app launches. • Improved practice-grid updates and formula checking. • Fixed weekday learning reminders so each selected day schedules correctly. • Simplified navigation to keep lessons, functions, practice, and the Playground easy to reach. • Improved table layouts, accessibility behavior, dark-mode support, and overall interface consistency. • Removed unfinished features and clarified which formulas the Playground supports. Thank you for learning with Xcell. Keep practicing—small improvements add up quickly.