Omni-Tools

Omni-Tools make engineers the technological wizards that they are. Strictly speaking, an Omnitool isn't a single device, but a system of which the engineer is a part. Physically there are a few large components scaterred throughout the body and brain, along with innumerable nano-machines which perform distributed computing using every cell in the Engineer's body. When in use for most purposes the omnitool manifests as a translucent gauntlet on one of the Engineer's arms.
True to it's name, the omnitool replaces nearly all other tools, capable of holographic projection and the manipulation of force fields, as well as the manipulation of matter at the subatomic level, an Engineer's omnitool is capable of feats that no other device can match.

An Omnitool handles an Engineer's computing and communications needs, while also allowing the use of Electronics and Build/Repair skills for most tasks unaided. It enables Engineers to use Tech and Hacking Abilities.
Due to the interface of their consciousness with their Omnitool, Engineers have a HUD that keeps them apprised of the various processes and calculations they're running at any given time. For especially visually-intensive information however, most prefer to use a holographic projection, as this avoids the need to split perception dice between simsense and the real world.