ELSA is an award-winning  app that that uses artificial intelligence to discern pronunciation mistakes made by English language learners. It consists of dialogues and games that allow for practicing all English phonemes, and provides immediate feedback.  (I am a native speaker of English, and I tried the activities  and was rated as 'native-speaker like' with scores ranging from 86-100%).  The designers have created an information page within their site containing resources and ideas on using ELSA in the ESL classroom .  There is a free downloadable app on Google Play and the App Store, but monthly/quarterly/annual rates provide upgrades that include a considerable number of additional features.