Wake up a PC on your network with your iPhone using Mocha WOL

First make sure your computer is setup to wake on lan in your BIOS setting. To check this, press the 'del' key (or F2, F10) when your computer starts to enter the BIOS. Verifiy that Wake on lan is 'on' then save and restart.

Now install Mocha WOL by MochaSoft from the App store on your iOS device and add the PC's IP address and MAC address to the app so that next time your PC is off you can turn it on with a press of a button on your iphone

Use a virtual home button on the iPhone

On the iPhone go to Settings,General,Accessibility and switch on AssistiveTouch. Now you'll have a white semitransparent button on the lower right corner of the screen that when you tap on will show you a Home, Siri button and other device short-cuts such as Volume, Mute and Lock-screen.

Print from your iPhone to a printer connected to your PC

In case you don't have an airprint enabled printer you still can print from the iPhone by installing the printer pro desktop helper on the computer that is connected to the printer (and has the printer drivers installed). Then get Readdle's printer pro lite to test your setup, and if it works you can purchase Printer Pro in the App Store. Remember the computer connected to the printer needs to be on (and on the same network) when you want to print from the iPhone.

Copy images and photos from PC to the iPhone's camera roll

Get Image Transfer by Capable Bits from the App Store in your iPhone. After launching the app click on 'Receive Photos' and enter the IP address on your computer's web browser on which you have the photos you want to transfer and select the photos you want to upload from you PC to your iPhone's camera roll album. Both computer and iPhone should be on the same (WiFi) network.

Connect your iPhone to a VPN server

Go to Settings, VPN, Add VPN Configuration..Choose PPTP. Type in any description and enter the server's IP address or the domain name of the vpn server. Type in the user account name and password for the vpn server and tap save.
Next time you want to connect to the vpn server with your iphone just select the configuration you did earlier and slide the vpn button to the right to initiate the connection.