IOpener is not a plug-in, it's an app that can start Photoshop and execute one or more actions and then save the image(s).
To do what you want, you would first record an action doing:
- Resize Image
- Write your text
- Flatten Image
Then start IOpener, point it to the source folder and select the action above from a list. After that, you press the execute button, and IOpener will open each image from the source folder, apply the three steps in the action and finally save the image in a sub-folder.
That should take a few seconds per image and you don't need to watch it, it will per default run through all the images in the source folder.
I downloaded IOpener and was running in 10-15 minutes.
Creating longer and complicated actions is another story though.
Regards
Michael