Another vote for iTarget from a certified firearms instructor.
Get it and practice when you feel like it. It is also the best way to teach kids shooting.
It will 100% improve your accuracy and speed and the cost is minimal. It pays for itself quickly and saves a ton of money every day after.
For those who conceal or open carry practice your draw and sight acquisition!
Those are two things I rarely ever practiced before and it helped me feel a LOT more comfortable. Really helped with trigger pull, too.