There's a LOT of great apps out there that can definitely help you study, especially if you have a commute or can only squeeze in 5-10 minutes here and there. These are the one's I'm into:

1. GMAT Toolkit - This is the most comprehensive GMAT app, with questions and information from MGMAT, Princeton Review, Manhattan Review, and Knewton. 900+ questions from those aforementioned test prep companies with an option to download 3000+ questions from GMAT Club, as well as an OG Tracker, Timer, Flashcards, and excellent SC and Quant review. It's pricey, but worth it for the serious test-taker. Cost: $24.99.

2. MGMAT Flashcards - A free set of Verbal flashcards, with a nice emphasis on applying vocabulary rather than rote memorization. Cost: FREE.

3. MBA Planner - This app by Clear Admit helps you organize the entire admissions process. You input your list of Target Schools, and MBA Planner creates To-Do lists to keep you on track to meet deadlines. You can also add personalized notes and contact information for each school. Cost: FREE.

4. Beat the GMAT Flashcards - Another free set of 300 GMAT flashcards covering both Quant and Verbal. What's not to love? Cost: FREE.

5. GMAT Practice Quiz - Veritas Prep's nice free app contains hundreds of practice questions organized by question-type, allowing you to hone in a weaknesses. One of the best in terms of test-prep companies' online offerings. Cost: FREE.

6. Your Teacher's GMAT -Problem Solving and Data Sufficiency help with 154 guided video lessons. A great way to refresh Quant concepts. Cost: FREE.

7. GMAC - OG 12th Edition - This is a brand-new app and a must-have! 800 questions from the Official Guide 12th edition in convenient app form! You can do mini-exams and select the number of questions you'd like, allowing you to study in shorter bursts on the go. Even if you've already completed the OG, it's worth reviewing again! Cost: $4.99.

8. GMAT Math Review - Impressive simply for the sheer number of questions. It boasts 2300+ questions for Problem Solving and Data Sufficiency. Once you've exhausted the free GMAT apps and still need more help with GMAT practice, this is worth picking up! Cost: $3.99.

9. GMAT Club - 111 Harder-level GMAT questions with explanations, designed for students aiming at a score of 700+. Cost: FREE.

Good luck!

Well, I would suggest you to use internet for preparation for your GMAT exams. You will get good study material, tips and suggestions to prepare to achieve a good a score for GMAT. Or else you can also use https://essaysapps.com, its the one best place to answer all your queries related to GMAT.

Many thanks for your support and help., Im half way through the algebra book and have 2 more mgmt quant strategy books to review before the next cat ..I'm planning to sit for the gmat in August