Whether you're a hardcore mobile gamer or just someone who likes to use games as a distraction to pass the time, basically everyone plays games on their smartphone and/or tablet. With the popularity of mobile games in recent years, however, we've also seen a rise in in-app purchases and higher-priced mobile games. But sometimes it's just hard to justify spending any additional money on virtualized currency or other in-game perks.Amazon gets that, and the introduction of the Amazon Appstore and Amazon Coins are the company's answer to high game and IAP costs. First off, let's take a closer look at what's going on with Underground.

Basically, the Amazon Appstore is a lot like the Amazon app that's already in Google Play, but it also includes access to the Amazon Underground program. This allows users to download games and apps as well as purchase all of the physical items available on Amazon all from the same app.

The Amazon Underground program offers "actually free" select content — a special selection of apps and games that are only available directly from within the app, called Underground Apps. What makes these apps so great is that they all carry the Actually Free label — that means the app, along with all of its in-app purchases, are completely free. No catches here, just completely free apps. These apps and games are always easy to point out, as they all carry Amazon's "Actually Free" banner across the top; when you see this, you automatically know that everything about the app is totally free.

Let's say that an app or game you want isn't available as part of the Underground program — that's where Amazon Coins come into play. With Amazon Coins, you can save money on both the initial cost of any app or game, as well as its IAPs, as Amazon Coins are the digital equivalent of "real" money. Each coin essentially equals one penny (so 100 Coins is $1.00), but Amazon takes savings off the top when Coins are purchased; for example, 500 Amazon Coins only cost $4.50 — a savings of 10 percent, or $0.50. The more Coins you buy, the more money you save: at the time of writing, 1,000 Coins are $8.80 (12 percent, $1.20 savings), 2,500 Coins are $21.25 (15 percent, $3.75 savings), 5,000 Coins are $40.00 (20 percent, $10.00 savings), and 10,000 Coins are $80 (20 percent, $20 savings). If you spend a lot of money on in-app purchases, the Amazon Appstore and Amazon Coins are a great way to get more bang for your buck.

There are also in-game ways to earn Amazon Coins. The company keeps a rolling list of apps and games that actually give up to 25 percent back in Amazon Coins on select in-game purchases. For example, if there is a 20 percent Amazon Coins offer and a purchase is made for $20.00, the user would get $3.99 (399) Amazon Coins automatically added to their account. Again, a great way to get more for less with the Amazon Appstore.

If you have an Amazon Fire device, then you're already on board with the Amazon Appstore, so you can jump in and get started right away. If you have another Android device, however, you'll first need to jump into the Settings > Security menu and enable installation of "Unknown Sources." From there, head over to this link to download the app and install it. Then all you need to do is enjoy the benefits of cheaper (or free) games and IAPs!