Matjaz just responded to an email I sent, and he stated that multi-monitor support is on their “to do list” and they “hope to have it soon.”
Knowing how awesome these devs are with updates, and responding to user suggestions, I am sure we’ll be seeing it soon.
IMO, this is the gold-standard of a software company. When you actually interact with the people using your product, and listen to their suggestions and desires, the program improves quickly, and the word-of-mouth about how good it is spreads just as fast. For example, I’m pretty active on Quora, and people there ask every day what program they can use to build their website, or how they can learn CSS or HTML, and I’m constantly recommending Pinegrow.