I've been testing several applications in order to add subtitles to my movies and videos and Subtitle Composer was chosen.
Select Video > Open Video to add your video you are willing to work.
With right mouse click in the line table you're able to add a new subtitle row in after and before position and you can remove them as well.
I will suggest to you to use shortcuts since is easier while typing and increment your velocity, the most common ones are.
Ins = Insert After
Ctrl+Ins = Insert Before
Del = Remove
Shift+Z = Set Current Line Show Time
Shift+X = Set Current Line Hidden Time
When you will finish to add subtitles to your movie, you will want to see common errors, the winner is overlapping times, with Subtitle composer you can mark them easily. Just select Errors > Check Errors
Unchecked them all except Overlapping Times, then click on OK button. Subtitle Composer will show you those errors on the line table.
Since there are a lot of options you might want to explore more, but the previous ones are the most used by me.
Here you can find more information about it.
Official site
Enjoy it!
