Artificial Gravity and Contragravity
It turns out that once the physics of gravity are fully understood, generating more of it within an enclosed system is fairly simple.
Space ships, stations, and facilities in zero or micro gravity environments commonly have artificial gravity.
Most high speed vehicles such as bullit trains, hypersonic shuttles, high speed elevators, and space ships traveling with STL drives also have artificial gravity with inertia dampeners for safety and comfort.
Gravity levels must remain constant within a closed system, meaning you cannot adjust the gravity level in one area without doing so for the entire system. Multiple artificial gravity systems may be used such as for different sections of a large ship or space station, but this is rare as most artificial gravity systems are built as an integral component of construction and multiple fields can cause imbalance and stres.
Operating an artificial gravity field within a larger field is possible and can be useful for generating a small area of higher gravity.
Gravity is very difficult to generate outside a closed system however. So gravitic weaponry is very limited as is planetary scale gravity manipulation.
Contragravity is a bit more complex, but its utility has made it a popular and reliable technology across the galaxy.
Contragrav generators require more power than artificial gravity and more bulky components.
Balancing the weight and power requirements of a contragrav system with the utility of it can be difficult, especially considering that most contragrav systems include multiple levels of redundancy for safety reasons.
At this point grav belts are not feasable, but grav suits, armor, and harnesses may be as they can mount heavier batteries or even micro fusion generators. These are expensive high-end items however, generally only seen in milspec or specialty and custom jobs. Grav-cars, bikes, and sleds are the common civilian contragrav vehicles.
Space ships expected to enter a planet’s gravity well also use contragravity assisted by vectored reactionless thrust and often an aerodynamic lifting body.
Hovering droids and drones can also use contragravity fairly easily as its requirements are integrated into the machine’s design. Small light weight models can often simply angle their contragravity fields to “coast” in their desired direction while heavier models include vectored air thrust to assist maneuvering much like other grav vehicles do.