Dragon Dictation is a free app which students can download to practice their speaking and pronunciation skills. It is a speech recognition application which is only available on the Apple iOS platform.
When I tried the transcription of my speech was 99% accurate. The only error was the absence of the definite article before Apple iOS due to the fact that structural words, such as auxiliary verbs and prepositions, are often pronounced in their weak form and so often go unheard (by electronic devices and students themselves!).
Learners can practice reading short extracts and compare their recorded transcription with that of the written text that they have chosen.