So if you are inside Middle East, you can download and install this app and then enable the video chat albeit Apple disable it.
Since it's a jailbreak app, thus your iPhone 4 have already been jailbreak already to use it. You can use tools, lika LimeRa1n, Greenpoi0n or PwnageTool to jailbreak your iPhone, afterward head to Cydia and search fo MiddleWhat and then install the app.
Then you can start enjoying the video chat feature in your region.
Don't ask me how this app going, because I don't live in Middle East, please give your review in the comment below if you live in such areas. So people can have reference before using MiddleWhat app and thank you for it.