How much can you save with coupons? That depends on how much time you invest. Time is money, after all, meaning that diminishing returns are an issue when you spend endless hours scouring the newspapers for coupons and dashing from store to store.

Couponing websites and apps have changed all of this, doing most of the work for you. You don't even have to open a newspaper, let alone subject yourself to endless paper cuts and wasted time. Try these money-saving apps to get discounts that couponers of the past could only dream about.

1. Shopkick

Lots of sites promise to give you points and rewards for shopping at various locales. All too often, the promise turns out to be a spammer's gimmick that leaves you flooded with unwanted emails. Enter Shopkick. The site and its app give you points, which can later be redeemed for gift cards, for shopping at your favorite stores. Even better, you can get points without spending any money — just by walking through the doors of your favorite shop.

2. RetailMeNot

Can't keep track of the promo codes your favorite stores email to you? Don't want to have to wade through piles of spam to find the latest sale at your favorite shop? RetailMeNot, usable as both a website and an app, helps you save time by compiling discount and coupon codes for thousands of sites. It primarily offers promo codes for online vendors, but you'll also find some information about upcoming sales.

3. SavingStar

If your wallet is overflowing with store loyalty cards, SavingStar is the app for you. SavingStar's app keeps track of all of your memberships in one place, alerting you to membership sales at hundreds of grocers and drugstores.

4. Groupon

Groupon is your one stop shop for saving big at local restaurants and service providers such as massage therapists and beauty salons. The site features regular sales with steep discounts of 30%-90%. You buy the Groupon discount upfront, then use the service when it's convenient for you. Groupon is available as both a website and phone app.

5. OneReceipt

You might not think of a receipt as a money-saving tool, but consider this: you probably buy dozens of products that fail each year. From the see-through dress to the plants that died as soon as you put them into the ground, it's hard to justify holding onto receipts for inexpensive items. OneReceipt compiles all of your receipts in one place, allowing you to check warranties easily and return faulty goods. All of this adds up to major savings, and could even make it easier to deduct eligible items on your taxes.

6. Gas Buddy

Sure, you could drive halfway across town to get gas at the cheap spot, or you could spend half of the day wandering around looking for cheap gas. This approach undermines the goal of saving by forcing you to guzzle gas to save on it. Gas Buddy is here to save you. This app helps you locate the cheapest gas near you, and constantly updates to ensure you always get the cheapest and most accessible option.

7. Out to Eat With Kids

Eating out with kids means a lot more than worrying about a spaghetti plate being flung across the room. It can also cost you a pretty penny. The cost becomes even more depressing if you have a picky eater who would rather complain about their sandwich than devour it. Out to Eat With Kids alerts you to kid-friendly restaurants with ongoing sales, including the much-coveted option for kids to eat free.

8. Coupons.com

Home to thousands of coupons for specific retailers, as well as general-use coupons, Coupons.com provides an app and website. Coupons are regularly updated, and the site only features coupons that have not yet expired, so you'll need to check back daily to get the most savings. You can even use the program's app to create a coupon-friendly shopping list that allows you to buy the least expensive items without rifling through a pile of paper clippings.

Couponing used to mean endless hours of planning and cutting, but with today's apps, there's no excuse for ignoring the money-saving power of coupons. Download a few today and begin saving now!