If you are anything like many people these days, you rely on your smartphone for all types of things. From making reservations to updating your status on social media, it can be used for various tasks. In fact, many people have decided to forgo a traditional map or GPS system (navigation on my phone) when seeking directions and they use their smartphones for this as well.
One thing that makes people rely on their phone is because it means they are not required to purchase an additional device. All they need to do is download an app and directions are right at their fingertips. There will be no need to head out to your local electronics store to grab a standalone unit. Basically, using your smartphone will save you some money.
A huge problem that exists when relying on smartphones to lead the way is the fact that you must have a signal in order for the apps in question to work as they should. If you are in a rural area, there is a chance you will not have mobile phone reception at all. In cases like that, it would be nice to have a map or standalone GPS on hand.
When using your smartphone as a GPS unit, it can be used hands-free. While you are driving and focused on the road, your phone can help you get from point A to point B. This is far easier than fumbling with a map and creating a hazardous driving situation or having to pull over to the side of the road. More info here, navigation on my phone
Smartphones are slowly making it unnecessary to buy additional devices, which may be a good or bad thing, depending on who you are and how it is perceived. Consider all of the points here before relying on GPS apps.