Best obfuscators for C# mobile apps

Which to learn

Pick C# if you want one codebase for Windows + Android + iOS (use .NET MAUI / Xamarin).

Pick Kotlin if you want native Android (best Android ecosystem support).

(If unsure: pick C# for cross-platform reuse; pick Kotlin for Android-first.)

Security / “data hiding” — reality

Both languages compile to intermediate code (Java→JVM bytecode / Kotlin→dex, C#→IL).

Neither prevents decompilation. Use obfuscation + server-side checks to raise the bar.

Essential protections to implement

Obfuscate code

Android: R8 (free) or DexGuard (paid).

.NET: ConfuserEx (open) or Dotfuscator (commercial).

License + device binding

Device fingerprint → ask your server for a signed license token (JWT-like).

App verifies token signature; token can be time-limited or bound to device ID.

Store secrets in Android Keystore / iOS Keychain.

Protect media

Store media encrypted (AES). Decrypt only at playback with keys delivered per-license or derived per device.

Prefer streaming encrypted content for strongest control.

Anti-tamper basics

Root/jailbreak detection, runtime integrity checks, fail-safe on signature/verification failure.

Tradeoffs (one sentence each)

Obfuscation + device-locked licenses deters casual pirates but won’t stop a determined reverse-engineer.

Moving critical logic/server checks off-device (server-side licensing/streaming) gives much stronger protection.

for Obfuscation is overrated for mobile apps. but tools exist for both java and c#.

the App Stores control only downloading purchased applications. you will need to follow their rules.

not sure what a NAS server has to do with the issue.

your application will require deep integration with the native sdks and may be difficult with a cross platform tool. if you are only looking at android, then use Kotlin. If IOS only, then Swift. if you plan on both then a cross platform tool like Maui might be a good choice, but will still require learning both native toolkits, and wrapping native code.