An Older iPhone

I'm in the market for a smartphone. I have an offer for a iPhone 4S for $100, fairly cheap. I am not sure if I want to get it though. I am not one to platform bias, I am pretty open, and if I were hard pressed to choose my favorite OS for a smartphone it would be Android.
The iPhone appeals to me for one reason, startups. I love the things and while there are quite a few that support both Android and iOS even more support iOS only.

The 4S is pretty, and has the start-up appeal I want, but it's old and could be bested by a budget Android phone at this point. Is it worth the buy, especially in the wake of the 5S and/or 5C?