App keeps crashing/freezing – GRE Prep by Ready4 Review

Hello, Like several users who paid 9.99 for the mobile version in hopes of receiving help to prep for the GRE, I am disappointed to see that the app keeps crashing/exiting out when I try to review answers and when I take the quizzes provided. It ends up wasting time and being counterproductive to prepping for the GRE. PLEASE FIX THIS.
Review by Anona3117 on GRE Prep by Ready4.