Projectile

Install the .zip file as an addon

Note that Projectile is compatible with Blender v3.0+

You can also support me by purchasing the addon on Gumroad (pay-what-you-want): https://gumroad.com/l/projectile

Trajectory Tracing: Projectile draws trajectories for each object so you can get an idea of how the object will interact with the scene.
Hassle-Free Physics: Projectile handles all the keyframing so all you have to do is set a speed and click a button! Much faster and more accurate than doing this manually.
Object Settings: Each emitter has its own settings tied to it, so don't worry about making a mistake because you can always go back and change something!
Real-World Units: Projectile will use the same units that are used in the .blend file, so you can use m/s or ft/s so you can truly know how fast your objects will be moving.

Usage

Projectile is located in the Physics tab of the sidebar

Click Add Emitter to set an object as a Projectile object. The execute operator will be applied and an empty (emitter) will be created at the same location as the object.
Click Remove Emitter with an active emitter to remove all instances.
Set the Velocity and Angular Velocity.
Number is to set the number of instances. (Default is 1)
Lifetime is to set the lifetime of the instances. 0 means the instances will not be destroyed.
Then click Execute, then you can play the animation and see the results.

Toggle between Spherical or Cartesian coordinates for velocity.
Choose a Solver Quality to increase the physics solver quality.
Draw Trajectories Has options to draw all, selected, or no trajectories in the 3D View

Projectile can be downloaded here for Blender 2.7x