What are some alternatives?
Liner - Put simply, Liner is a virtual highlighter. It works on PDFs and webpages in the same way a regular highlighter works on books and magazine clippings. Read more about Liner.
ScreenToGif - This tool allows you to record a selected area of your screen and save as a animated gif.
Paperpile - Clean and simple and reference management for the web. Sync your PDFs to Google Drive and cite your papers in Google Docs.
GifCam - GifCam is a handy and reliable application designed to record the screen and to convert the...
Mendeley - Easily organize your papers, read & annotate your PDFs, collaborate in private or open groups, and securely access your research from everywhere.
LICEcap - A straightforward, high performance application that enables users to capture a portion of the desktop and save it to . GIF or . LCF, LICEcap is available for download as a GPL free software.