Structured learning
Course progression with lessons, stages, topics and completion tracking.
Pre-launch educational product
Learn C# by actually using it.
A structured mobile learning experience combining lessons, interactive quizzes, practical coding exercises, progress tracking and gamification in one Android-focused platform.
C# Course
Continue your learning journey
CURRENT STAGE
C# Fundamentals
PRACTICE
Interactive Quizzes
CODING
Practical Exercises
PROGRESS
Streaks & Achievements
Product depth
Not a demo. A substantial learning product.
The course already contains a large structured C# curriculum, practical exercises, localized learning content and extensive automated validation.
94
C# course topics
1,700
indexed learning activities
826
lesson units
874
coding tasks
2,346
lesson steps
977
knowledge checks inside lessons
4
complete language versions
1,000+
automated test definitions
A complete learning foundation.
C# Course is more than a collection of screens. It combines the learning flow, user accounts, progress systems, localization, subscriptions and backend infrastructure required for a serious educational mobile product.
Interactive quizzes
Question-based learning with feedback, explanations and progress states.
Coding practice
Practical programming exercises designed to move beyond passive reading.
Progress & gamification
Learning streaks, completion indicators and progression-oriented UX.
Four languages
English, Polish, Ukrainian and Russian localization with in-app language switching.
Premium subscriptions
Direct Google Play Billing with backend-authoritative premium access.
Curriculum
From first program to advanced .NET concepts.
The curriculum contains 94 topics and 187 structured subtopics across three learning levels, progressing from C# fundamentals to advanced language, platform and software-engineering concepts.
29
Beginner topics
49
Intermediate topics
16
Advanced topics
Content scale:
1,369 explanation/information steps, 977 in-lesson knowledge checks and 849 embedded lesson code blocks.
Every supported language contains approximately 18,502 localized course entries. Across English, Polish, Ukrainian and Russian, the project contains approximately 967,159 localized words of learning material.
EN ≈ 253k words · PL ≈ 245k words · UK ≈ 233k words · RU ≈ 234k words
The application interface itself also contains 339 localized UI strings per language.
1,369 explanation/information steps, 977 in-lesson knowledge checks and 849 embedded lesson code blocks.
Every supported language contains approximately 18,502 localized course entries. Across English, Polish, Ukrainian and Russian, the project contains approximately 967,159 localized words of learning material.
EN ≈ 253k words · PL ≈ 245k words · UK ≈ 233k words · RU ≈ 234k words
The application interface itself also contains 339 localized UI strings per language.
View the complete 94-topic C# curriculum
01
What is C# (C Sharp)
02
Program structure: Main + top-level statements
03
Getting started: your first program
04
Console I/O (WriteLine / Write / ReadLine)
05
Variables and types
06
Variables and constants (const)
07
Type conversion: Parse / TryParse / Convert
08
Literals (numbers, chars, strings, null)
09
Arithmetic + assignment + type conversions
10
Bitwise operations (bitwise operators)
11
Conditional expressions: comparison and logic (bool)
12
Conditions: if / else / else if + ?:
13
switch statement
14
Loops: for / while / do..while / foreach
15
Arrays + array tasks (iteration, 2D, jagged)
16
Methods: declaration, call, parameters and return
17
Variable scope
18
Recursion (recursive functions)
19
Local Functions
20
Enumerations: enum
21
Classes and objects
22
Namespaces and using
23
static (fields/methods/class)
24
Math calculations and the Math class
25
const, readonly fields, and readonly struct
26
Properties (get/set), auto-properties, init, required
27
Access modifiers (public/private/protected/internal...)
28
null, nullable and operators ?. ?? ??=
29
Constructors, initializers, deconstructors
30
Class: fields, methods, constructors, properties
31
Structs: creation, constructors, initialization, with
32
Partial classes, methods and properties (partial)
33
Value vs Reference: value types vs reference types
34
System: Object, String, Console
35
Type aliases and static import
36
Global usings (global using)
37
System.String: string, Unicode/UTF-16, alias System.String
38
Interpolation, verbatim strings (@), StringBuilder
39
Exceptions: try/catch/finally (basics)
40
Generics: T, multiple parameters, generic methods
41
Collections (basics): List, Dictionary, Queue
42
Collections: Stack and LinkedList
43
Method overloading (basics)
44
Dates and time: DateTime, DateOnly, TimeOnly
45
Dispose, finalizer and using (IDisposable)
46
OOP: encapsulation, inheritance, polymorphism, abstraction
47
Inheritance: base class, derived class, base, sealed
48
Type casting: upcasting, downcasting, is, as
49
Virtual methods/properties: virtual, override, base, sealed
50
(yield) Interfaces and structs (IInterface + struct)
51
Iterators and yield return / yield break
52
IEnumerable and IEnumerator (how foreach works)
53
Arrays and indexers
54
Indices and ranges (^ and ..)
55
Span and ReadOnlySpan (no-copy memory)
56
Overloading: methods/operators/constructors (different aspects)
57
Delegates: Func, Action, Predicate (usage + differences)
58
Parameter passing: value / ref / out / in / params
59
Ref locals and ref returns (ref local / ref return)
60
Extension methods
61
Tuples (Tuple): creation and element access
62
Anonymous types
63
Records (record, with, init)
64
Pattern Matching
65
LINQ basics: Where, Select, OrderBy, GroupBy
66
LINQ: data projection (Select, let, SelectMany)
67
LINQ: sorting (OrderBy / ThenBy / IComparer)
68
LINQ: set operations (Union / Intersect / Except / Distinct / Concat)
69
LINQ: aggregate operations (Count / Sum / Min / Max / Average / Aggregate)
70
LINQ: taking part of a collection (Skip/Take/SkipWhile/TakeWhile)
71
LINQ: grouping (group by / GroupBy)
72
LINQ: checks and element retrieval (All / Any / Contains / First / Last / Single)
73
LINQ: joining collections (Join / GroupJoin / Zip)
74
LINQ: deferred vs immediate execution
75
LINQ: delegates in queries (Func, Predicate, method group)
76
PLINQ: AsParallel and ForAll
77
PLINQ: AsOrdered and AsUnordered (result ordering)
78
PLINQ: errors (AggregateException) and cancellation (WithCancellation)
79
LINQ: filtering (Where / OfType / complex filters)
80
System.IO: streams/files/directories + serialization basics
81
Regular expressions (basics): System.Text.RegularExpressions
82
Events — basics and examples (GUI)
83
Class relationships and multiplicities
84
Object model (building an object model)
85
Generics: creating your own generic class
86
Reflection + attributes (getting info about methods/types)
87
Multithreading and async: System.Threading (Thread/Task/Mutex)
88
Networking: System.Net (HTTP, WebClient/HttpWebRequest)
89
Databases: System.Data (SQL, SqlConnection/SqlCommand)
90
XML: System.Xml (XmlDocument/XmlReader)
91
ORM / object-relational mapping + CRUD in EF
92
SOLID
93
Design patterns
94
Unit tests
Buyer value
Much more than a Flutter template.
A buyer receives an existing educational product foundation, not just screens that still need the core systems to be built.
Large ready-made curriculum
94 C# topics, 826 lesson units, 874 coding tasks and 1,700 indexed learning activities.
Multilingual from the start
English, Polish, Ukrainian and Russian course content plus localized application UI and in-app language switching.
Built-in monetization architecture
Direct Google Play Billing, server-side verification, premium entitlements, purchase restoration and subscription plan-change support.
Server-authoritative subscriptions
Google Play Developer API verification with Firebase Functions, RTDN and Google Cloud Pub/Sub reconciliation.
Security-oriented backend
Firebase App Check, authenticated backend calls, entitlement ownership protections and production-oriented security validation.
Progress & retention systems
Persistent progress, learning streaks, gamification, completion tracking and local/cloud persistence.
Practice-focused learning
Multiple-choice learning checks, practical coding tasks and terminal-style practice instead of passive reading only.
Extensive automated validation
212 automated test files across Flutter, backend and emulator suites with more than 1,000 test definitions.
Substantial existing codebase
Approximately 46,157 lines of production Dart/JavaScript source across the mobile application and backend, excluding automated tests.
Launch-oriented tooling
Release validation, security checks, subscription infrastructure and Google Play/Data Safety preparation are already part of the project.
Free + premium content architecture
Course access is already designed around separate free and premium learning content rather than requiring a monetization redesign later.
Easy expansion path
A buyer can add new C# content, additional programming courses, more languages, achievements, analytics and growth features on top of the existing architecture.
Production-oriented architecture.
The project uses direct Google Play Billing with server-side verification and entitlement reconciliation instead of relying on client-side subscription state.
Flutter Android App
→
Google Play Billing
→
Firebase Functions
Google Play Developer API
→
Firestore Entitlements
→
Premium Access
Flutter
Dart
Firebase Auth
Cloud Firestore
Firebase Functions
Firebase App Check
Google Play Billing
Google Play Developer API
Google Cloud Pub/Sub
SQLite
Current status
Advanced pre-launch stage.
The core product, learning system, backend and subscription infrastructure are already implemented. Current work is focused on final QA and visual polish before a potential production release.
✓
Flutter Android application
✓
Authentication and user profiles
✓
Structured lessons and quizzes
✓
Coding exercises and practice system
✓
Progress and gamification systems
✓
Four-language localization
✓
Direct Google Play subscription architecture
✓
Automated Flutter and backend testing