Technology has come a long way and the ability to create decent recordings is now at our fingertips. However, the built-in mic's on our smartphones, tablets, laptops and desktops are not the highest of quality. It is best to connect a quality mic to these devices.
All that being said, a "fair" recording is still achievable with your device's built-in mic. You just need to be intentional with how you use it. The following articles have good tips for being intentional: