Hello my name is Andrew,
I am a member of the Simkl team (https://simkl.com).
We're looking for someone to help the Simkl community and develop an open source Plex plugin for Simkl that would sync watched history with Simkl using the API: http://api.simkl.com.
We're offering a $200 reward to help create this plugin. If you have any questions know someone who can help, we'd like to hear from you at support@simkl.com