This is a bad idea for several reasons. It destroys employee morale, there are legal implications depending on what state you're in, and if you spend all your time making sure others are doing their jobs, then when do you do your job?
Micromanaging like that, especially at startup stage, is just going to kill your company. You'll drive away the people working for you now, then you have to replace them. You should know better than most people how expensive it can be to hire someone. Not to mention the unemployment you'd have to pay out, and potential lawsuits you'd have to defend yourself against whether or not they have any legal merit. You will very quickly drive your company out of business because you didn't know how to trust people to do their jobs.
If you have reason to believe some employee isn't doing their job, then probably the best thing to do is to talk to them about it, not spy on them. Maybe there's a perfectly valid explanation for what appears to be them wasting time. Maybe there's not, but after a couple minutes chatting with you about it, they shape up a little. Compare that to the couple of hours, minimum, you'd likely need to find enough evidence to fire them and be able to successfully defend yourself against a wrongful termination suit. Not to mention the expenses you take on posting an ad, sorting through applicants, conducting interviews, all the taxes and associated expenses that go with hiring someone, the fact that it'll take them a couple of weeks at least to get up to speed so there's lost productivity... Every time you fire someone then everyone else starts wondering if they're next, is the company in financial trouble, basically the focus becomes less and less about their job and more about the office drama you created.
If your business is going to succeed, you're going to have to learn to let go at some point. Now is as good a time as any.
I'm sure this is not what you wanted to hear, and I fully expect to get some sort of "How dare you tell me how to run my company blah blah blah... I asked a simple question, and didn't need your self-righteous opinions blah blah blah" type response. That's fine, I'm a big boy, I can take it... A response like that just means I'm not telling you anything you didn't already know, but didn't want to admit to. Just keep what I say in mind, and once you've had a chance to cool off, think it over. I bet you'll find that there's a lot of truth in what I say.