App: iSubtitle 3
Developer: Bitfield AB
Genres: Photo & Video, Productivity

Inject subtitle tracks, chapter markers and metadata into your movies and TV-shows. The perfect companion app for your iTunes library and all your Apple devices, like the iPhone, iPad, iPod, Apple TV and Mac.

iSubtitle takes full advantage of Apple's soft subtitle technology. The subtitle tracks are resolution independent and rendered in real-time as you watch the movie. Subtitles are always displayed at the best quality your device can perform. There are support for multiple languages in the same movie file and you can even switch language on the fly as you watch. The export and metadata tagging is fully automated so you don't need to tweak a lot of parameters to get your movie into iTunes with beautiful tagging and artwork.

Main Features

- Add soft, non-destructive subtitle tracks, that won't change or alter the original movie.
- Subtitles can be turned on/off using the interface of the device or application.
- Complete support for multiple languages in the same file.
- Perfect integration with your iTunes library or the TV app on macOS Catalina/Big Sur.
- Supports all Apple devices like the iPod, iPhone, iPad, Apple TV and Mac.
- Supports encoding in AVC, aka H.264 and HEVC, aka H.265.
- Supports pass through for H.264 and H.265 video tracks and AC3 and AAC audio tracks, ie no encoding needed = fast!
- Supports all major subtitle file formats like SubRip (.srt), SubViewer 1 & 2 (.sub), SubStation Alpha (.ssa/.ass), Spruce (.stl), iTunes Timed Text (.itt) and WebVTT (.vtt).
- Matroska subtitles, like ssa/ass and srt, are automatically converted to soft subtitle tracks on import.
- Sync individual subtitle tracks in real-time using the time offset stepper.
- Automatic and manual metadata tagging.
- Create chapter markers automatically or manually.
- Batch re-encode movies within the application to support your target device or application.
- Smart export will only re-encode your movie if really needed for it to play on your device.
- Save inline directly to the source file if it's already in a compatible mp4/m4v format.
- Watch subtitled movies in fullscreen without leaving the application.
- Hardware decoded playback on the GPU for H.264 and H.265 video tracks in any container.
- Works like a charm with macOS Catalina and Big Sur. 

• Please use the Feedback feature in the app if you are having issues and I will get back to you!

NOTE! iSubtitle cannot add subtitles to movies or tv-shows purchased or rented in the iTunes store due to DRM protection.
NOTE! iSubtitle is not a subtitle file authoring application.

Release notes:
- Playback with hardware decoding on the GPU for H.264 and H.265 (HEVC) video tracks.
- Playback with hardware decoding also works for containers like .MKV (Matroska)
- Playback with hardware decoding saves battery life and CPU cycles.
- Easily plays 4K video when hardware decoding is available.