A lot of apps are free to download, but what about an app that pays you to have it?

Earn about $5 a month with Slidejoy app

Several members of my staff and myself have tested a free app called Slidejoy for some time now. Slidejoy serves ads up on your phone's lock screen, and you get paid to view them.

With Slidejoy, when you download the app and ads appear on your lock screen, you just slide them off to get to your home screen. Sliding to the right dismisses the ad immediately. Sliding to the left takes you to the advertiser's website, video or download page for more information.

So what do you get paid to have Slidejoy on your phone? My producer Joel averaged about $5 a month using Slidejoy. (The money can be remitted via check, PayPal transfer or donated to a partner charity.) Slidejoy is only available for Android at this point, but they've been promising to release an iOS app for some time now.

As for me playing around with Slidejoy, so far I've viewed ads for the Adidas Spring Blade Razor shoe and a Groupon offer for Puma men's boxer briefs that cost $16.99. $16.99?! Really? Boy, they got the wrong guy for that offer!

 

Other advertisers Slidejoy is working with include Sephora, MeUndies.com, Best Buy, Target, J. Crew, and Macy's, according to the app's maker.

Read more: Best cell phone plans & deals for 2016

Get $5 off your wireless bill with this app

Meanwhile, Boost Mobile has a new offer for its customers. You can get $5 off your month bill if you download the Boost Dealz app.

Once you have the app on your phone, it will serve you ads each time you swipe the lock screen. Keep it running in the background and you'll get a statement credit of $5 every 30 days. It's that easy.

Boost Dealz is only available for select Android phones. Sorry, iPhone people who are on Boost Mobile!

Read more: Apple wouldn't give this woman access to her dead husband's devices

Want more money-saving advice for your mobile device? See our Mobile & Electronics section.