On our first floor we installed 2 inch door latches on the window frame for security. Works as a window stop and no one can lift our windows higher than the latch. Yet we just retract it if we want to open the window all the way.
Close interior doors silently: the Latchy Catchy are small accessories for doors that help to prevent undesirable noises and slamming doors that can wake the baby. They are adjustable, economical and a good gift for expectant moms.
Latch Door - The door opens when all locks and latches are undone. Would be fun somewhere outside as an entrance to a play area - just be sure there is a second way out in case a sibling locks it while you're inside lol