How to control/provision bandwidth allocation in my home Wi-Fi?

I know the Q is probably a bit too long, but i want everyone to know that i'am not selfish, so please keep reading…
i used to have an internet connection using a satellite sorta(i have no idea what its called) on my roof, the connection was pretty fast, but i didn't had Wi-Fi which is something that was necessary to get because i only have one computer at home witch i share with my whole family( 5, my parents and my little sis and bro) so i recently bought a device from another internet provider that allows you to connect to the internet while sharing Wi-Fi at home, all in one device and all you have to do is to plug it to a socket and made sure it was near a window, and let the device do its job, i was pleased with the results the internet was quite fast however i solved a problem and another one pops up outta nowhere, almost my whole family have smartphones, my dad has a nokia asha( the touch one without the keyboard) my
brother has an android phone i have an iphone 4 and even my little sister has a PSP witch also has built-in Wi-Fi, so the situation is already messed up, but my brother is a video addict and he also likes to download games from his store and one time the page didn't load so i took my brother's phone and i found him downloading 5 F***IN VIDEOS AT ONCE! I didn't know what to do! And he was wondering why the video download speed was so slow! So i wanna share my bandwith equally, i don't wanna pay like 150$ a month just because my family uses so much bandwith, and i certainly don't want to get rid of the Wi-Fi, is there any app that allows me to control the bandwith? Anything! Even if i have to install an app on my brother's android phone, please help me!

What you need is quality of service and throtling, this is not something that any domestic router does well. Your best bet is to setup your own firewall, get hold of a cheap old pc and install something like smoothwall on it. And attach that to your router. It has options for quality of service and limiting bandwidth built in.
And before anyone else shouts up smoothwall is not the best option but if your a newb its a good one as its really friendly to set up.

What the other answerer said is correct. You need a Wi-Fi router that supports Qualify of Service (i.e. QoS). None of the inexpensive consumer routers do what you want with QoS. To do what you want you will need something like a Cisco 800 series router. Http://www.cisco.com/en/US/products/ps9555/index.html

I don't advocate running a firewall on an old PC, as the PC will become the bottleneck. PCs don't make very good routers.