Caption - Open-source captioning tool to help find the right subtitles.
Subtly - Learn English with smart subtitles on movies and TV shows
Bazarr - Bazarr is a companion application to Sonarr and Radarr that manages and downloads subtitles based on your requirements.
Video Subtitle Maker - Add captions directly to your videos online
CaptionPop - Watch YouTube videos with multiple subtitles simultaneously
VEED Subtitle - A simple & fast way to add subtitles to your videos online