Overleaf - The online platform for scientific writing. Overleaf is free: start writing now with one click. No sign-up required. Great on your iPad.
Adobe Acrobat DC - Make your job easier with Adobe Acrobat DC, the trusted PDF creator. Use Acrobat to convert, edit and sign PDF files at your desk or on the go.
TeXworks - The TeXworks project is an effort to build a simple TeX front-end program (working environment)...
Sumatra PDF - Sumatra PDF is a slim PDF/DjVu/EPUB/XPS/CHM/CBR/CBZ/MOBI viewer for Windows.
Archimedes - Archimedes is a LaTeX and Markdown editor designed to make mathematical writing easy.
Wondershare PDFelement - All-in-one PDF editor