# Tennis Blackbox — Challenge Line Calls Like Pros > Challenge Line Calls Like Pros (iPhone/iPad app by Jee Hoon Park.) - Source: https://appshunter.io/ios/app/tennis-blackbox/id6474873410 (this page in markdown: same URL + `.md`) - Developer: [Jee Hoon Park](https://appshunter.io/developer/1583942288) - Category: Sports, Photo & Video - Price: Free with in-app purchases - Age rating: 4+ - Requires: iOS 16.6 · 85 MB - Languages: American English, French (France), German (Germany), Hindi, Indonesian, Italian, Japanese, Korean, European Portuguese, Russian and 4 more - Released: 2024-02-08 - Data updated: 2026-08-20 - User reviews in markdown: https://appshunter.io/ios/app/tennis-blackbox/id6474873410/reviews.md ## What is Tennis Blackbox? Tennis Blackbox turns your iPhone into a powerful tennis match recorder and analyzer. Use a dual-device setup to capture every rally in 240fps slow motion, then review your play on an iPad or second iPhone. RECORD - Capture matches at 240fps for detailed slow-motion playback. - Seamless recording with no gaps between video segments. - Automatic frame verification ensures full quality capture. ANALYZE - Automatic court direction detection using on-device machine learning. - Ball tracking with trajectory visualization powered by OpenCV. - Browse footage with broad and detailed thumbnail timelines. MULTI-CAMERA CONTROL - Connect multiple iPhones as cameras over your local network. - Live H.264 video preview from each camera at 30fps. - Monitor up to 8 courts with smart resource management. DUAL-DEVICE SYSTEM - iPhone records your match hands-free as the camera. - iPad or second iPhone monitors and analyzes as the controller. - Devices connect automatically over local Wi-Fi. DESIGNED FOR TENNIS - Landscape interface optimized for court-side use. - Save videos to your photo library for easy sharing. - Supports 15 languages. Whether you are a coach breaking down match footage or a player looking to improve your game, Tennis Blackbox gives you the tools to see what you missed on the court. ## Pricing and in-app purchases Base price: Free. **One-time purchases** | Purchase | Price | Type | | --- | --- | --- | | 1주 사용권 | $6.99 | one-time | | 1달 사용권 | $14.99 | one-time | | 1년 사용권 | $99.99 | one-time | | 하루 이용권 | $0.99 | one-time | | 하루 이용권 | $1.99 | one-time | ## Version history (last 5 releases) ### 8.2 — 2026-08-14 What's New in Version 8.2: Standby Power Saving - Cameras enter standby automatically 60 seconds after the iPad disconnects. - The screen turns off and recording pauses, cutting battery drain and heat. - Reconnecting the iPad wakes them instantly, ready to record again. Recording Improvements - Recording now stops a moment later, so the final seconds are fully captured in Slo-mo. ### 8.1 — 2026-03-29 What's New in Version 8.1: Match Review (10fps) - Record the entire match as a composite video from all connected cameras. - Review match scores and plays in-app with fast/slow sliders — no need to open Photos. - Press Load > "Match Review (10fps)" to browse and play back recorded matches. Line Call Review (240fps) - Renamed for clarity: high-speed camera footage for precise line call decisions. - Now saves the last 20-40 seconds for more complete review coverage. Connection Stability - Cameras no longer crash when iPad disconnects or restarts. - Much faster reconnection when restarting the iPad app. - Battery and temperature info now updates via status polling (no extra requests). Recording Improvements - Recording cancel (long-press Stop) now properly stops all spinners. - Save/cancel confirmation shown as toast notification. ### 8.05 — 2026-03-19 What's New in Version 8.0: Live H.264 Video Streaming - Real-time H.264 video stream from iPhone to iPad at 640x360 / 30fps, replacing the old JPEG-based preview with dramatically smoother, sharper live video. - Smart decoding: inactive court tabs skip video decoding to save resources, ready to scale up to 8 cameras. Performance and Stability - Fixed memory leaks and improved error handling. - Eliminated gaps between video recording segments. - 240fps capture is verified before recording starts. UI Improvements - Fixed button display issues on iOS 17+. - Cleaned up interface elements for a more polished experience. ### 8.0 — 2026-03-17 What's New in Version 8.0: Live H.264 Video Streaming - Real-time H.264 video stream from iPhone to iPad at 640x360 / 30fps, replacing the old JPEG-based preview with dramatically smoother, sharper live video. - Smart decoding: inactive court tabs skip video decoding to save resources, ready to scale up to 8 cameras. Performance and Stability - Fixed memory leaks and improved error handling. - Eliminated gaps between video recording segments. - 240fps capture is verified before recording starts. UI Improvements - Fixed button display issues on iOS 17+. - Cleaned up interface elements for a more polished experience. ### 7.28 — 2025-07-16 Periodic Update ## Apps similar to Tennis Blackbox | App | Rating | Price | Category | | --- | --- | --- | --- | | [Fast Tennis : Habit Correction](https://appshunter.io/ios/app/fast-tennis-habit-correction/id6471351884) | — | Free | Sports | | [eyes3 LineCall & InstantReplay](https://appshunter.io/ios/app/eyes3-linecall-and-instantreplay/id1478586247) | 4.0 (4) | Free | Sports | | [In/Out Sport](https://appshunter.io/ios/app/inout-sport/id6471904224) | 2.3 (3) | Free | Sports | | [ServeOn - Tennis App](https://appshunter.io/ios/app/serveon-tennis-app/id6471379978) | — | Free | Sports | | [EasyTennisScore](https://appshunter.io/ios/app/easytennisscore/id6753675661) | — | Free | Sports | | [타이브레이크](https://appshunter.io/ios/app/id6476483336) | — | Free | Sports | ## More apps by Jee Hoon Park - [Family Tree - 가계도](https://appshunter.io/ios/app/family-tree/id6758861517) - [Gyeot](https://appshunter.io/ios/app/gyeot/id6760648358) - [뉴스백신](https://appshunter.io/ios/app/id6760929007) All apps by Jee Hoon Park: https://appshunter.io/developer/1583942288 --- *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 2026-08-20.*