Ask HN: Is AWS Free Tier a viable option to cut down initial cost for a product?

I and my friend are trying to launch a product(something like Instagram for a niche market) However, both of us don't have any experience with hosting yet. We need someplace to host that can support at least a 100 or so people so that we can at least show it to others before we can launch it. So is AWS Free Tier good for that, or should we look for some alternatives?