Simulate different network conditions on iOS simulator

http://nshipster.com/network-link-conditioner/

When enabled, the Network Link Conditioner can change the network environment of the iPhone Simulator according to one of the built-in presets:

• EDGE
• 3G
• DSL
• WiFi
• High Latency DNS
• Very Bad Network
• 100% Loss

You can control the internet downlink/uplink bandwidth. BitTorrent/UTorrent some times won’t respect the upload limit so network-link-conditioner will control it.

how to uninstall unnecessary simulators in Xcode?

You can find and delete the simulators from the path /Library/Developer/CoreSimulator/Profiles/Runtimes. Restart Xcode in order to take effect.

or

You can delete a simulator from Xcode by navigation through Menu > Window > Devices > Simulators.