The post history say April 28th was the release of 1.3 (the current version). From what I can recall the cycle of release is fairly long. I am expecting something "soon" (as in before the end of the year).
The dev keeps telling me to join the discord to track update progress but I'm lazy.
updates are big as I always add scenes for all the girls. but you can expect something like more than 1 hour of content for each month I spent working. (I post previews almost every day on discord btw)