# BeatDropX — 50ms Precision Rhythm Engine

> 50ms Precision Rhythm Engine (iPhone/iPad app by 应龙 张.)

- Source: https://appshunter.io/ios/app/beatdropx/id6770849281 (this page in markdown: same URL + `.md`)
- Developer: [应龙 张](https://appshunter.io/developer/1514562080)
- Category: Games
- Price: Free
- Age rating: 4+
- Requires: iOS 17.0 · 1 MB
- Languages: American English, Chinese (Simplified, China)
- Released: 2026-05-24
- Data updated: 2026-07-30
- User reviews in markdown: https://appshunter.io/ios/app/beatdropx/id6770849281/reviews.md

## What is BeatDropX?

BeatDropX is built on a professional-grade rhythm engine architecture, designed for players who demand precision.

Technical Specifications:
• Judgement accuracy: Perfect ±50ms / Good ±100ms / Miss ±150ms
• Rendering engine: SpriteKit at 60fps real-time note fall
• Audio-visual sync: AVAudioPlayer sampleTime-driven, frame-level alignment
• Haptic system: CoreHaptics CHHapticEngine + UIImpactFeedbackGenerator dual-channel

Beatmap System:
• 3 built-in tracks (120/140/160 BPM), SplitMix64 PRNG for reproducibility
• Difficulty scaling: Easy 1 note/beat, Normal 2/beat, Hard 4/beat + 18% chords
• User import: AVAudioFile frame-level RMS differential + adaptive threshold onset detection
• Auto-generates Easy/Normal difficulty beatmaps for imported songs

Scoring Mechanics:
• Perfect 1000pts / Good 500pts / Miss 0pts
• Combo bonus: +5% per 10-hit streak, capped at +50%
• S/A/B/C/D rank system (≥95% accuracy = S rank)
• UserDefaults-persisted personal best records

Interface & Adaptation:
• SwiftUI + SpriteKit hybrid architecture
• iPad adaptive layout (lane max width 500pt)
• TimelineView-driven beat-breathing background animation
• Runtime bilingual switching (dynamic Bundle lproj loading)

Privacy:
• Zero network requests, zero third-party SDKs
• No data upload, 100% offline operation
• Delete the app to delete all data


## Version history (last 1 release)

### 1.0 — 2026-05-24

No release notes.

## More apps by 应龙 张

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- [Cube Master Studio](https://appshunter.io/ios/app/cube-master-studio/id6768941523)

All apps by 应龙 张: https://appshunter.io/developer/1514562080

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-07-30.*