Educational tools have changed dramatically in the past few years with the rising popularity of smartphones. The challenge our society now has is to embrace these new tools so they become mainstream. Here are some highly rated apps that offer a good start.Apple appsStack the States (99 cents) -- Kids and adults alike will love learning about the 50 states, including geography, historical facts and more. (Mobilewalla Score: 99/100)Fit Brains Trainer (Free) -- Give your brain a workout with thousands of brain-teasing games that were developed by renowned neuropsychologist Dr. Paul Nussbaum. (Score: 95/100)Vocabology -- Word of the Day (99 cents) -- Improve your vocabulary with this simple yet effective technique of repeated use of the daily word. (Score: 94/100)Quizlet (Free) -- Learn one of 18 languages using a massive database of flashcards. Not connected to the Internet? Download the cards and study offline. (Score: 92/100)HowStuffWorks (Free)* -- Ever wanted to know how GPS works? Or why brain freeze occurs? Find out in this beautifully designed app. (Score: 87/100)Android appsStar Chart ($2.99)* -- Point your Android device's camera at the night sky and see the stars as you never have before. (Mobilewalla Score: 95/100)Mathway (Free)* -- Students and parents both will appreciate the step-by-step instructions and answers to math problems across a number of subjects. (Score: 89/100)Reading Trainer ($3.99)* -- If you want to read faster and comprehend more efficiently, you have to train your brain with the proper techniques, provided in this tutorial. (Score: 87/100)School Assistant + ($1.79) -- Better manage your school workload with this smart scheduling and progress-tracking app. (Score: 87/100)MapMaster -- Geography Game ($1.65) -- Learning world geography can be fun. Get clues about a place on the map, and pinpoint it. (Score: 85/100)*Available on Apple and Android.Mobilewalla is a search and discovery engine using breakthrough technology to score every app to help consumers navigate the mobile application marketplace. Apps are scored using an algorithm that weighs several characteristics, including user ratings, position within category and staff recommendations. For more app intel, go to www.mobilewalla.com. Anindya Datta is a technologist and founder of Mobilewalla.