How to keep track of programmers' hours worked?

Question

Work organization

At the moment, we have contracted several programmers for hourly pay. They do their job perfectly, much better than when we worked with programmers on a per-project basis.
The question was how to make sure. that the programmer works out his stated time? What is the service or program for tracking time and immediately set the price there.

Answer 1

You work with people, you like everything, the quality, and I understand the cost, but you still want to control and save. But why? Still good, it works - don't touch it, don't you?
And so, work through odesk for example.

Answer 2

I use this
crocotime.com/ru