CleverPDF is a comprehensive PDF web app, which offers 27 PDF tools online for free. It helps users convert PDF to Office, iWork, images and more. Users can also compress PDF, merge or split PDF, rotate PDF, add watermark or numbers to PDF and more. It's completely free, no sign-up is required.
Tesseract - Tesseract is an optical character recognition engine for various operating systems
PDF Joiner - This online tool allows you to join several PDF documents into a single file, free of charge.
GOCR - GOCR homepage. GOCR is an OCR (Optical Character Recognition) program, developed under the GNU Public License.
DocuPUB - DocuPUB is an online file converter, file merger, file compressor, and file resizing tool.
TextGrabber - Office & Productivity
PDFChef Merge PDF - PDFChef Merge PDF is an online tool that allows you to merge multiple PDf files into one quickly and securely.