In 2013, the average test taker spent a little over a month studying for the GMAT, totaling between 50 and 100 hours of study time according to a GMAC survey.

Not surprisingly, the survey found that those who scored the highest also studied the most.

Test takers who scored at or above a 700 studied an average of 102 hours total while those who scored between 600 and 690 averaged 92 hours and those who scored between 500 and 590 only studied 78 hours on average.

Though the time you spend studying does not dictate your score – many other factors contribute to how you perform on the test – it’s tempting to wonder what impact an additional 10 hours of prep could have.

GMAT apps help fit test prep into your schedule

The value of additional studying is obvious, but the dilemma for many professionals and students studying for the GMAT is fitting more study time into their already packed schedules. With mobile apps, however, you can take test prep with you, turning a daily subway commute into time for practicing questions or a lunch break into a review session.

An extra 20 minutes of studying a day equals 10 more hours of studying a month, which could make the difference between a high score and a retake.

A variety of apps are available to sharpen your test prep, and we’ve outlined the strengths of the five best GMAT apps below. Of course, we’re a bit biased since we make a GMAT app, but each app listed, including our own, tackles GMAT prep in its own way, so it’s important to find what works best for you. Try a few out and use what helps you the most.

The official guide for GMAT review app

Produced by the GMAC, the makers of the GMAT, the Official Guide App offers practice questions for each part of the test. When practicing questions, you can toggle between “Exam mode” and “Tutor mode”. The first fires off question after question like on the actual exam while the latter gives instant feedback after each question you answer, providing an explanation of why the right answer is correct.

The strength of this app lies in its questions. Since it is made by the same company behind the GMAT, it uses authentic GMAT questions retired from the test. Downloading the app costs $4.99, and you may purchase additional packs of 250 questions for $9.99.

Prep4GMAT

Prep4GMAT features hundreds of questions, lessons and flashcards, but it’s more than just a study course in an app: It’s a GMAT trainer that helps you master GMAT questions by teaching you how to recognize the concepts behind the questions. Each practice question can be highlighted using an X-ray feature to reveal the question’s keywords, which in turn helps you learn how to solve the question.

The app also features detailed analytics, which break down your practice performance to reveal your strengths, weaknesses and pacing for each question type, so you know what you need to study the most. Prep4GMAT is free but currently only available for iOS users. The Android version will be released soon.

Magoosh GMAT Prep

The Magoosh app, which complements the company’s GMAT prep course, provides video tutorials on numerous verbal and quantitative subjects as well as the AWA section. Concepts include percents and ratios, powers and roots, and coordinate geometry in the math section and the parts of speech, verb form, and diction in the verbal section. GMAT organization and strategy is covered in an intro section.

The app is free to download; however, many of the videos require a Magoosh Premium subscription to access and watch, which costs $99 a year.

Veritas

Like Magoosh, the Veritas app explains GMAT concepts and questions through a series of videos that you stream or download to the app. Videos are divided into 12 modules. While the modules cover verbal and quantitative subjects, most modules focus on math topics, such as arithmetic, statistics and combinations, or geometry.

Veritas is available free for download, and most of the app’s videos are also free.

Khan

GMAT prep is just one of the 1000s of subjects covered by Khan Academy, the non-profit education company, and you can access their GMAT prep lectures through the company’s GMAT apps. Khan has produced four GMAT apps: GMAT Problem Solving 1 and 2 and GMAT Data Sufficiency 1 and 2. These subjects are taught through video lectures using a digital chalkboard.

Each app focuses on a set of questions from the official guide, and within the apps, the videos dissect the official guide questions, showing you the best way to solve them. In the process of explaining the questions, the videos cover important math concepts, so even if you don’t have the official guide to follow along with, you can still learn the concepts behind math questions.