Varsity Tutors LLC has developed a free Android app, Common Core Math 4th Grade, specifically designed to help fourth-grade students build their math skills. The app is a continuation of the knowledge gained in previous years, with a focus on simple multiplication and division, basic fractions, calculating the area of two-dimensional shapes, and how to use angles and their measurements.

The Common Core Math 4th Grade app has a free diagnostic test that helps students identify areas that need more attention. The app has over 150 free practice tests and thousands of flashcards, which are organized by concept to help students find the resource they need quickly. Every answer on the practice tests has a detailed explanation, allowing students to understand the "hows" and "whys" of any concept. Additionally, the app has a "question of the day" feature that is perfect for quick math chats when time is limited.

Overall, the Common Core Math 4th Grade app is an excellent tool for students looking to reinforce their math skills on a regular basis. The app is easy to use and can make the process of talking with students about their math skills easier and more enjoyable.