Yes the images are stored forever but there is no way to get to them again. If you need to post the same image again, you would need to upload it again.
However, often I just find an old post of mine with the image I need, click on "edit", copy the whole post or just the image material, close the edit window, and then post the copied material into a new post with stuff edited out to fit the new situation. Sometimes this is easier for me instead of looking for the image again on my computer.
By the way, the credit for developing that app belongs to the moderator of this forum -1492.
Barney