Probably not. I mainly use Preview and a folder on iCloud Drive and they are both free. On Windows PrtSc does the job. Linux has a free tool too. Also, if I'm

Probably not. I mainly use Preview and a folder on iCloud Drive and they are both free. On Windows PrtSc does the job. Linux has a free tool too. Also, if I'm storing it in my S3, why am I paying you? An example of what I would pay for, Screencast-o-matic - it lets you create screencasts and optionally stores them for you in the cloud. If I was doing a lot of screencasts I would probably pay for that service rather than clog up space somewhere else.