A system which in some embodiments comprises a wireless smart device assembly that includes a smart device, wherein the smart device assembly is attachable or mountable against an unopened surface of a wall or other structure. In some embodiments, a system comprises a smart device assembly that includes a smart device; and a fastener that includes adhesive and is coupled to the smart device assembly and releasably attachable to a wall or other structure. Some embodiments include a level indicator configured to indicate the angular position or orientation of one or more other portion of the smart device assembly relative to parallel and/or plumb to the force of gravity. In some embodiments, a mount and/or a cover define a catch to releasably attach the cover to the mount.