I had a nice chat with Ryan at play later support
The upshot of the conversation is
That play later records directly to your pc, in real time, while the video is being delivered to your pc from the source site
The play later software controls the access and recording, but it is done on your pc, their server provides ready access and redirects for network programs, and uses your subscription info for services from Netflix, HuLu plus, etc..
Your pc must be on and must be connected to the internet for the recording to happen
Once recorded on your pc in mp4 format, you can move/ copy the recorded video to any other device that supports mp4