Go with the (cash) flow

Since the invention of mobile payment systems in 2000, more people are using phones for money transactions. This latest wave of "going mobile" is being spearheaded by millenials who are quick to adjust to the newest forms of technological innovation.

As of now, the smartphone is set on track to become the wallet of the 21st century.

According to TechCrunch, 90 percent of smartphone users will have made a mobile payment through a smartphone browser or app, such as PayPal and Venmo, by 2020.

Here is a review of the five most popular mobile payment apps, rated on a scale of one to five in the following categories: cost of fees (pricing), convenience, safety, speed of transaction, and popularity. We also give an overall score, taken as the average of the five categories.

Venmo

Venmo

Photo: A Venmo user sends money to a friend.

A Venmo user sends money to a friend. Photo courtesy of PayPal.

Pricing: 4.5/5

Convenience: 4/5

Safety: 4/5

Speed of Transaction: 4/5

Popularity: 5/5

Overall score: 4.3/5

Processing more than $1 billion a month, Venmo is an extremely popular app with many unique features to offer. It provides users with the option to split a bill between friends, as long as they are all Venmo users. In addition, Venmo boasts a social appeal by displaying user payment activity on a social feed for friends to see. Venmo's security is also notable, with data encryption and secure servers guarding against unauthorized transactions and access to personal information. However, there is a potential for scams, since payments take a couple days to clear. If you're using this app to trade goods or services for cash, make sure the money reaches your account first. Other disadvantages of Venmo include low payment limits and a 25 cent fee for each instant transfer.

PayPal

Pricing: 4/5

Convenience: 4/5

Safety: 5/5

Speed of Transaction: 4.5/5

Popularity: 5/5

Overall score: 4.5/5

PayPal is one of the most popular payment services out there, with 237 million active and registered accounts in 2018. Because of its following, PayPal is an accepted form of payment at many stores and commercial websites. It has earned the trust of mobile payment users through its buyer and seller protection for goods and services. It is also one of two apps on this list that allow users to send money internationally. Unfortunately, it can only transfer money to other PayPal users, includes transaction fees for debit cards and doesn't have a bill-splitting feature like Venmo.

Xoom

Pricing: 3/5

Convenience: 4/5

Safety: 3/5

Speed of Transaction: 4/5

Popularity: 4/5

Overall score: 3.6/5

Xoom is the other app on this list that users can use to transfer money to people abroad. In fact, it is specifically geared towards international transactions. With Xoom, users can send payments to people in over 70 countries, but the same cannot be said in the opposite direction: the cash only flows out of or within the country. Unlike PayPal, the recipient doesn't even need a smartphone -- they can pick up cash at a local bank with a code and an ID. The biggest downside about Xoom is that upfront fees aren't all you need to factor in. Be careful of the exchange rates and transaction fees, though, as you might end up with a worse deal than you expected.

Square Cash

Pricing: 4/5

Convenience: 3.5/5

Safety: 5/5

Speed of Transaction: 5/5

Popularity: 3/5

Overall score: 4.1/5

Although not as widely used as PayPal and Venmo, Square Cash is a good choice for users who want a simple, no-nonsense mobile payment app. Its interface is practical and easy to navigate, minus the features and frills of other apps. With Square Cash, money is deposited in your bank account automatically. People without a Square Cash account can send or receive money through email or text, and the app's Cash.me pages allow virtually anyone to send you money without asking for personal information. In addition, its security is the same as that used by major credit cards. With that said, Square Cash has a low daily payment limit and doesn't work in web stores.

Zelle

Pricing: 5/5

Convenience: 3/5

Safety: 5/5

Speed of Transaction: 5/5

Popularity: 2/5

Overall score: 4/5

Zelle is a new app launched by major American banks including Chase, Wells Fargo and Bank of America. It allows their customers to pay their friends directly from the bank's app without downloading another one. An advantage of Zelle is that it doesn't charge a fee for moving the money. The money is transferred directly to your bank account instead of a holding area as with Venmo and Square Cash. However, these instant and free cash transfers can only be made if both parties are customers of Zelle-partnered banks. Overall, Zelle is a quick and trustworthy app for customers of participating banks, but it has few benefits to offer otherwise.

After an in-depth look at these five mobile payment apps, PayPal ends up coming out on top. With its large user base and dependable security features, this app is the best choice for the average smartphone user. For people simply looking for a quick and easy way to send and receive money, Square Cash is the best option. Xoom places last in this review because it has too many additional fees and is only useful for international transactions.

Do you agree that PayPal is the best mobile payment app? Let us know what you think!