Subtitle Synchronizer for '.srt' files, what you do is figure out what is the offset in time, if using SMPlayer you can vary the delay of the subtitles with 'Z' and 'X' keys.
When it looks good, remember the value and put it in this application, with the corresponding operator plus or minus sign.
Drag the .srt file to the application, or shift+right click on top of the file and press the context menu option.
On the press of "Save" button, the original file will have the suffix '.bak' and the file that was dragged will be modified with the new timings.
Note this only works if the subtitle has the same time offset throughout the entire duration of the film. This is more of a subtitle offset corrector than a synchronizer, i think, but anyway.
Remove from context menu at any time by calling the application with /remove, or while its running, go to traymenu and press remove.
Hope it serves you well.
Many thanks for the people who helped, you know who you are.