5 Apps Busy Executives Use to Work Smart The right apps are as close you can get to adding a twenty-fifth hour to your day.

No matter how hard you try, you really cannot create more time in your schedule. What you can do, however, as an in-demand executive, is control how finite and effective you are with the time you have. Fortunately, among the estimated 1.5 million apps they have available for iOS or Android, many developers have taken the time to design mobile apps exclusively for business professionals and busy executives.

Using the Applause APPS for Business Executives Index, my colleagues and I selected five apps that executives should evaluate. Each app received a high and favorable rating among C-level and corporate leadership respondents, and these apps represented some of the most efficient ones in terms of productivity available for mobile use.

Related: The 5 Best Productivity Apps for Entrepreneurs

As corporate leaders and executives become increasingly mobile, concerns regarding browsing and data safety are at the forefront. Do you know how to tell if the wi-fi network you are accessing is actually safe? Can you collaborate and share files with your team safely, or communicate seamlessly through a messenger app? We chose five essential mobile apps that executives shouldn't be without.

1. Duolingo.

For many executives, business takes them into international territories, and having the ability to speak in more than one language (even at a basic functional level) is helpful. The Duolingo website and app received an 88.5 percent mobile sentiment approval rating for executives in a survey conducted by Applause, in 2016.

The software takes the hardship out of learning a second or third language, with a gamified interface that makes it easier for people with busy schedules to learn. Executives can break up linguistic sessions into five, 10- or 20-minute daily sessions, and click along to learn written, vocal and audio cues to help them rapidly learn the language of their choosing, anywhere and anytime.

Try Duolingo on mobile.

2. WhatsApp.

If you are not using WhatsApp, chances are that you have been introduced to it by a colleague, or business associate. In August of 2014, the messaging mobile application had 600 million active users. In January of 2015, WhatsApp grew to more than 700 million monthly active users, with approximately 30 billion instant messages sent between professionals every day.

Why the popularity? When you travel internationally, text messages and roaming charges can become costly. Getting into Facebook Messenger only recently became easy, with a separate advertisement free app that didn't require logging into the social network. It was cumbersome, and in the game of real time messaging and VOIP calling, Facebook seemed to lose the race to the small, user friendly WhatsApp.

Try WhatsApp on mobile.

3. Slack.

Looking for something that functions similar to WhatsApp, but includes private chat spaces, drag and drop file functionality? Something that also has the ability to organize different departments into unique communication channels? Welcome to Slack, the most inaptly named productivity app on the planet.

In July of 2016, there were 930,000 daily active users (DAU) with paid accounts on the Slack network, and three million registered users worldwide. Approximately 77 percent of Fortune 500 companies use the program for data sharing and mobile collaboration, according to data provided by DMR Stats and Gadgets.

Users refer to themselves as "Slackers," and that is part of the popularity and unique culture of the app, which carries the slogan "Be less busy." The app was repurposed from a failed game design, and received a 64.5 percent approval rating on the 2016 Applause Mobile Sentiment Analysis.

Experience Slack on mobile.

4. CamScanner.

Traveling light for business can be a challenge, until you realize that there is a plethora of apps available that can actually replace bulky equipment. For instance, many executives require a scanner for contracts and documentation, but traveling with one may be cumbersome.

Although scanner hardware has evolved to provide new hand-held wand scanners, there is an even better, smaller and more convenient tool for busy professionals; your smartphone.

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How does it work? You simply open the app and using the built-in camera of your smartphone, move the camera over the document to scan a clear image, which is then converted from a jpeg to a pdf document. Once the file has been converted, it can be manipulated, encrypted and even stored in the cloud.

The CamScanner app turns your phone into a mobile scanner, but the premium version is capable of much more, including:

• Creation of a doc collage with multiple pages.
• Batch.pdf file downloading.
• Multiple collaborators on each document.
• Data sync across multiple devices and users.
• 10G of cloud space.

Some very crucial tools for security are included in the premium version of CamScanner, including the ability to password protect documents, and set a customized expiration date of the document link, which is ideal for time sensitive contracts and other business applications.

Try CamScanner on mobile.

5. CM Security.

This "all-in-one" security app is used by an estimated 84 percent of executives, according to Fortune magazine. Not only does the app provide protection and encryption of data on the mobile device (tablet or smartphone) but it also provides other features, including an "app lock" interface that helps protect folders, files and private apps from being accessed. The impressive app can even tell you if the public wi-fi network you are accessing is safe, and helps protect users against Wi-Fi phishing, while boosting browsing speed.

A brand new feature introduced by Cheetah Mobile in version 1.2.4 allows the mobile user to browse all major search engines privately. You no longer have to worry about having your user identification revealed when you are browsing competitor sites or other information, and the CM Security app automatically deletes the complete browser history upon exiting the app.

Download CM Security for Android.

Related: 4 Essentials for Successful Mobile Apps

This is essential for executives who collaborate in private cloud groups, or intranets. Unfortunately, the app is available for Android users only through Google Play.