DogTools is a Blender addon built to help place objects, originally made by developer Dog012 for constructing pipes and joints. The developer later found it fit other tasks too, including placing objects, connecting cable, playing chess and navigating. It is described as a Blender 2.8 addon and is listed as compatible with Blender 2.81.
The addon works largely through the mouse and snapping. It offers face-to-face snap, random distribution and shuffling of objects, alignment with spacing, and discrete rotation driven by the mouse wheel with a preset. You can use the mouse to teleport an object, duplicate it or create a linked duplicate while snapping to the face under the cursor, and to set an object's origin. A separate pie menu addon, DogPie, toggles built-in features such as auto-smooth or changes the editor type.
The download includes introductions and a readme.txt with the shortcut and setup instructions, which the developer suggests reading before installing. A chess asset the developer made is available to download as well. Distributed under the GPL license, the current version is 0.1.4, and version demo videos are available on the developer's page.