1)   Bytescout Form Filler 1.23 RC1
Fill scanned paper forms in fast and easy! Program detects text fields automatically to so just open scanned form image (or scan directly using software) and click "AutoFind Text Fields To Fill" and then just type in text using keyboard

 2)   pdf-FieldMerge 4.0
With some few mouse clicks pdf-FieldMerge allows to fill in existing PDF form fields automatically. PDFs may be processed singularly or en masse - automatically or manually with pre-selected data - without detour of Acrobat Reader