However, there is one drawback and that's that the target phone needs to within 150 feet for the program you have to work. You simply need to install the software onto your phone and ensure that the Bluetooth on your own phone is turned on. Once the target phone becomes in range, then the software will start syncing with the target phone if it's enabled on that phone. You need to know the phone number of the target phone to be able to distinguish between devices, too. Once the phones are finally synced, too, you will be given a menu full of options.
Another popular option is FlexiSpy. This is a great program that lets you eavesdrop and do Global Positioning System and email tracking. It even allows you to make remote phone calls from your target phone. Since 2010 it has cost between $150 and $350 though, making a more expensive alternative. Once you've purchased it you need to install it on the phone. Remember that this can take two hours so you'll need to have uninterrupted access to the phone for this period of time.
Then there's Mobile Spy. Since 2010 this program has cost around $50, and once you've purchased the software you just need to install it on the target phone by first installing it on the computer and syncing it with the phone. The program works with iPhones, Blackberries and Androids.