Background Timesheet is a Blender add-on from Shynez that handles multiple background images as a timesheet, in the style of an anime timesheet. It's typically used for 3D layout and 3D guide work in 2D anime projects, letting you make background image keyframes from several image files.
The tool lives in the Animation category of the 3D viewport's Sidebar. You set the scene's current frame to where you want it, click Add, and select an image file, then change the current frame or click a list item in the camera view. Adding an image inserts background timesheet keyframes onto the active camera and changes the render resolution to adjust the image size. A Reset Keyframes button clears up most common keyframe issues.
It's written in Python and runs on Blender 4.2 LTS, with versions 5.0 and above unsupported. Version 0.7.1 sets the curve interpolation of background timesheet keyframes to CONSTANT. The add-on requires no special permissions and is released under the GNU General Public License v3.0 or later.