The 
Redstone Wrench is your main editing tool for Tiny Redstone builds. Once a circuit is placed, you rarely want to break and replace everything to make a small change, and the wrench lets you rotate, configure, and remove components without disturbing their neighbors.
Rotating and reorienting
Right-click a placed component with the wrench to rotate it. This matters most for directional parts like Tiny Repeaters, Tiny Comparators, Tiny Observers, and Tiny Pistons, which only pass or act on signals from a specific side. If a repeater is not powering what you expect, rotate it until its output faces the wire you want to drive.
Removing single components
Sneak while using the wrench, or use it on a component you want gone, to pick that one piece back up without clearing the whole face. This is the safe way to fix a miswired cell in the middle of a dense circuit.
Practical workflow
Build a rough layout first, then use the wrench to fine-tune orientation. Keep the wrench in your hotbar whenever you are debugging, because most "my circuit does nothing" problems are just a component facing the wrong way. Test each stage with a lamp as you go rather than wiring the entire build before checking it.