The best I can do here is a Mac tutorial, for Bluestacks but I am sure it's similar to the PC.
1) Go to: BlueStacks
2) Scroll down and pick your download; Mac or PC.
3) Save your .dmg or .exe to anywhere you want, preferably your desktop.
4) If you're on the Mac, drag your Bluestacks Application to the Applications folder but if you're on the PC, then I think you should install it to your hard drive.
5) When you start BlueStacks it should ask you about terms and conditions; Just accept them.
6) On the BlueStacks Application there will be a blue search button, click it and type the name of the app you're looking for; In this case it would be iFruit.
7) A quick tip: Go to the settings in the bottom right corner then click 'Manage Accounts' then click Add Account and add your google account.
8) If the iFruit app is compatible with your phone that is registered with your google account then it should search and then it should be downloaded.
8) If not, then harsh luck.