OCR with GUI for correcting mistakes?

Question

I've used SimpleOCR, which has a nice GUI for correcting mistakes. Unfortunately, it makes a lot of mistakes! (and suffers other bugs and limitations)

On the other hand, Tesseract is more accurate but has no GUI at all.

My question is, is there a free OCR program which has a nice GUI and a low error rate? I want it to highlight suspect words (by OCR uncertainty, not just spell checking) and show the original (bitmap) word while I'm editing the OCRed word similar to what SimpleOCR does.

Open-source would be best, followed by freeware, then trial / demo / crippleware a long way behind. Windows or cross-platform is preferred, Linux acceptable, Mac unacceptable.

_{(I originally asked this question on Super User long before this site existed. It definitely belongs here, but you can't migrate questions older than 60 days so I'm copy-pasting)}

Answer 1

gscan2pdf is a GUI for several engines, including tesseract.

https://www.youtube.com/watch?v=UjjogfWfWsQ

It works best for cleaning up and OCRing scanned books.

Fair warning: the interface does not highlight suspect words or have spellcheck. Also, it puts one image per page, so don't use it on existing PDFs if you want to preserve the formatting.