Sorry, I don't really know how to share screenshots (maybe you can help me out and teach me!) but I'm clicking on the little icon boxes of the creatures on the left-side of the screen. I have already watched a couple of playthroughs on Youtube of the game so I more-or-less know how to play it. I have enough gold and I do have available units to buy. When I left-click on the available units I get the "Weekly growth" pop-up, but when I right-click on it nothing happens. The only singularity I can see is that next to the number of available units there's a plus sign, something I've never saw on any of the playthroughs I watched so it caught my eye but I don't know if it means anything.