There's an app for everything — even saving some money every month on your phone bill!

Everyone likes to save a little cash when it comes time to pay the monthly cell phone bill. Once you've done all your homework and found the plan that's best for you from the company that offers the best service there are still a few things you can do to make sure you're not spending too much on things you don't need or want. Like everything else, there are apps for that!

Here are five apps that can help you trim a little fat from your monthly phone bill.

My Data Manager

You should only be paying for the data you need. While some carriers like Google's Project Fi only bill for the exact amount of data you use each month, most companies don't give credit for data paid for but not used. That means paying for the right amount is pretty important.

Ways to monitor how much data you use are probably built into your phone, but the best way to make sure we use any software utility is to make it easy. Enter My Data Manager. Track how much data you use through mobile and Wi-Fi with roaming data accounted for separately, keep track of voice minutes and text messages, track shared or family plan data totals and more all from one app or home screen widget. Finally, My Data Manager also has what's called a Plan Matcher that keeps track of plans offered in the U.S. and can help make sure you're using the right one based on your usage history.

Download: My Data Manager (free)

WhatsApp

Stop paying for texts or for any international texting plan. Just stop right now!

WhatsApp was designed to replace SMS plans from the ground up because in most places around the world texting isn't "free" or built into the monthly plan costs — just like international messaging for many plans in the U.S. And there are now over a billion daily users because it's really good at it. Spending the extra money to text a friend or relative overseas is crazy when you can do it better for free.

Download: WhatsApp Messenger (free)

Skype

Those same friends and relatives who are outside the U.S. might enjoy a phone call every now and then, too. Of course, those aren't usually part of your "free unlimited voice calls" either.

Skype is to voice calls what WhatsApp is to texting — a better way to do it that doesn't cost any extra cash. Both parties install the free app and set up an account with Microsoft (you probably already have one of these anyway) and you can make calls that usually have the same or better quality than they would if you just called the "regular" phone number.

There are a ton of apps that can do this, but since Microsoft is behind Skype we're pretty sure it's here to stay and isn't suddenly going to stop working. As a plus, you can use Skype on any computer with internet access, too.

Download: Skype (free)

Your cable company's Wi-Fi network

Chances are you have cable television, and chances are the company you pay for it offers a Wi-Fi network you can use with your account login.

The way this works is through an app that notices when a Wi-Fi hotspot through your cable company (Comcast, Time Warner, AT&T, whoever) and when it finds one you connect through it instead of your data plan.

It's "free" as in its part of your monthly cable bill, it's secure because it's not a public Wi-Fi network and it's automatic so you won't need to remember to do anything. All you need to do is install the right app and set it up.

Datally

Datally is a relatively new service from Google you've probably never heard of. But you will be glad you did if you want to see about saving some money on your cell phone bill.

It's a data monitor with a twist — it also uses your phone's built-in tools to set up a local VPN (no data goes to Google or outside of your phone, ever) that can block or manually dole out data access to specific apps that you define. Use this in tandem with My Data Manager to find the very best plan that fits your needs and stop paying any extra money.

Download Datally (free)