ChatSim is a SIM card that offers users the ability to message on certain apps for a baseline price of $12 per year.

An Expedia.com study recently revealed what most suspected: The majority of travelers consider their smartphones to be the most important item to bring on trips. But signing up for and using overseas calling plans offered by U.S. wireless companies are among the most frustrating, and among the most expensive, experiences consumers encounter in their journeys.

Travel advisers have taken note: The importance of keeping their clients connected internationally has not escaped them, and many are now offering more convenient options for staying connected, including applications that enable cheap international calling via WiFi, in an attempt to combat the historically expensive and confusing international plans offered by most domestic carriers.

T-Mobile is now including in some of its simple choice plans international roaming in about 140 countries with unlimited data and texts. The plans start at $50 per line per month. WiFi calls made back home to the U.S. are free, but WiFi calls to another country are 20 cents per minute, the same rate as cellular calls.

Other carriers have more complicated  — and more expensive — ways to make international calls. For example, AT&T offers a three-tiered plan for coverage in some 190 countries with base charges of $30, $60 and $120. Each includes unlimited texting, but depending on the base plan, a user could pay as much as $1 per minute for calls and more for data.

In contrast, Wireless Traveler offers several popular solutions that travel advisers can share with their clients. In addition to renting and selling global phones, the company has an eponymous app that offers international calling for as low as 2 cents per minute over WiFi. It is a  voice-over-Internet-protocol (VoIP) service that is available wherever there is WiFi.

Rates vary by country, but for example, a traveler in France could call another country from the app for 3 cents per minute. Calling another person who has the app is free.

The company also offers a white-label version of the product, working with agencies and tour operators such as Valerie Wilson Travel and Collette Tours to create branded apps that offer the same calling technology. Wireless Traveler also has preferred-supplier relationships with Virtuoso, Ensemble Travel Group and others, according to CEO Ian Benson.

Valerie Wilson Travel Co-President Kimberly Wilson Wetty said she uses her company’s branded app when she travels and is impressed with the quality of the service for the price.

“It is the cheapest thing I have ever used as a service,” she said, calling the quality “so clear it was unbelievable.” Her agency promotes the app to its clients, including leisure and corporate travelers.

Wetty particularly likes that the app carries her agency’s name and logo, keeping it in the forefront of clients’ minds.

“As an agency owner, that’s one of the concerns as we look at the increased advancement of travel technology,” she said. “How do you maintain your own brand and your own relevance in a world where there’s information 24/7 and completely at your fingertips?”

Elaine Carey, an affiliate of Travel Experts, uses the app as a gift that she gives to some of her younger, more tech-savvy clients. Before they travel abroad, she pre-loads an app with $20 for them. It also provides them with a good — and free, for them — way to get in touch with her if something goes wrong on their trip, she said.

Benson said that while some agents do gift within the app, “not enough [do] in my opinion. … I think it’s a fabulous gift to give to somebody because it’s so relevant.”

Nicole Mazza, chief marketing officer of Travelsavers and NEST, said the companies encourage their agents to gift WiFi calling credit within their Affluent Traveler Talk App. Many use it as a value-add for their clients.

In addition to the Wireless Traveler app, the company offers global SIM cards, which Benson said are his biggest sellers. They work in most countries in the world through partnerships with some 400 carriers. The card costs $24.99, with $15 of free airtime included; it also includes a U.S. and European phone number.

Rates vary, but for example outgoing calls from France to the U.K. have a 40-cent connection fee and are 65 cents per minute. Text messages and data are available at additional per-country costs.

Like the Wireless Traveler app, Benson said there are agents who gift global SIM cards to clients, as well as the company’s pocket WiFi hotspots.

It is important to note that Wireless Traveler’s global SIM cards only work on unlocked GSM cell phones, meaning they will not work with Verizon handsets.

Travelers could, of course, purchase local SIM cards if they have a compatible phone once they reach their destination, but Benson said

he only recommends that for longer stays because it eats into vacation time, and the local cards cannot travel from country to country. They also expire after a set amount of time, while the global SIM card does not.

ChatSim, another relatively new international telecom service, is making its way into the U.S., and its investors are hoping agents here will start using the technology themselves and gifting it to clients, as the company is seeing internationally.

ChatSim is a SIM card that offers users the ability to message on certain apps for a baseline price of $12 per year. The card itself is also about $12, but it does not expire at the end of the year.

ChatSim works on messaging apps WhatsApp, Messenger, LINE, WeChat, imo, Kakao Talk, QQi, Hike and BBM. It provides coverage in 150 countries by connecting to over 250 service providers.

Pierre Brais, an angel investor in ChatSim, said the company differentiates itself from others thanks to its flat annual $12 fee to chat within compatible apps. The card can be ordered online through Amazon for $25, which includes the card and the first year’s $12 fee.

For an extra $12, users can buy a multimedia package of 2,000 credits, which they can use to send photos and make voice calls within apps. ChatSim estimates 2,000 credits would give a user enough bandwidth to send up to 200 photos or 50 videos or make up to 80 minutes of voice calls. Brais said around 60% to 70% of people buying the card are also buying the multimedia option.

Costs are kept down by preventing other apps on a user’s phone from running in the background, eating up data, according to Brais.

“Our tests have shown that 90% of data traffic on a smartphone now is used by the background applications on your phone,” he said, not by what the user is actually doing. The ChatSim card automatically turns off non-messaging apps to limit the amount of data used.

ChatSim has been on the market for about a year, and 100,000 cards have been sold, including to travel agents and tour operators, who are gifting the cards or selling them to clients.

The company attended the recent New York Times Travel Show and got a positive reaction from agents, Brais said, marking the start of ChatSim’s push into the U.S. market.

Brais said the card works in most unlocked, SIM-capable phones, both GSM and CDMA, meaning that unlike Wireless Traveler’s SIM cards the CDMA version of ChatSIM will work with Verizon handsets.