There's no GM screen in OSR+ partly because we roll in the open, but also because the rules are simple enough that you won't need to open a rulebook to look things up!
Whether you're a new or veteran GM, we recommend keeping a copy of the GM Cheat Sheet handy, which is downloadable below. This document will keep you honest on target numbers and remind you of weakness tags to exploit.
The GM Cheat Sheet also includes a guide for GM disadvantage. For example, if a player method is cautious, then the flubbed outcome would be overreach. This helps in crafting consequences for poor rolls and success at a cost. You'll find a quick reference for the mechanical rules on tactics and perils as well.