A³E (Automatic Android App Explorer) is a guided exploration tool for Android. A³E generates test suites by conducting app exploration using two different strategies. First, A³E employs a novel guided exploration tactic that first creates a high-level model of the app by creating the Static Activity Transition Graph (SATG), and then intelligently selecting app entry points optimized to deliver a speedy exploration. A³E also facilitates a depth-first approach for app GUI testing that mimics a human tester by dynamically generating input sets.