LoveByPDF

Click Add Signature, draw/type/upload it once, then click on the page to place it. Choose Same spot, every page above first if you want it copied to the whole document automatically. Drag a placed signature to move it, click it to select it, use the corner handle to resize, and the × to remove it - Delete/Backspace and Undo (or Ctrl/Cmd+Z) also work once something's selected.