..This Newborn extender is great for gluing subfloor.  It has a guide that lets you follow the joist (or double joists) while you gun out the adhesive.  I have 2 of these and would not be without them.  They can also save your back while epoxying concrete cracks. (also known as crack chasing). Another great labor saving tool.
The Newborn Brothers extender caulking gun is a long 45-inch caulker ideal for sub-floors, ceilings, walls, and roofs. Features include double-reinforced steel support rods, a t-bar, and a reversible 2-in-1 joist guide for added versatility. The gun also features a 1.4-gallon, 30-ounce barrel with an easy-grip handle and thumb release, an all-steel, welded construction for professional-grade durability, and a seal puncture tool with built-in spout cutter for easy refilling on the fly.