Hello,
I have tested your nice client today, and it looks very good already, congrats :-)
In the Google Reader API (implemented by FreshRSS), there is the concept of starred articles, which are well mapping with your "read later" concept. It would be nice to sync them, i.e. retrieve the list of starred articles to show in your "read later", and the other way around.
Feel free to ask if I can provide any documentation.
Alkarex, from FreshRSS