English Synonyms Dictionary with Sound is really two apps in one -- a thesaurus/dictionary and a text-to-voice reader -- both of which work but without anything more than the basics. Setup and use are straightforward, but for advanced features, certain words, and integration between the two functions, you'll likely need to look elsewhere as this app doesn't go beyond its core offerings.
There are two options when starting English Synonyms Dictionary with Sound. The first is to search for words that will then provide a basic definition and a list of synonyms. It really is a halfway point between dictionary and thesaurus as it provides decent definitions, but almost entirely made up of synonyms. It has an auto fill search function and you can change its filtering methods to be strict or a little looser. Nonetheless, it is not a fully comprehensive dictionary as a handful of words we entered, usually different tenses of verbs like "taught", "ate", and "ran" did not appear in the results. What did appear offered a handful of synonyms and a text-to-speech option, however. Additionally, there is a second menu at the bottom offering you text-to-speech functionality for anything you type in.
If you need a bare-bones thesaurus and text-to-speech tool, English Synonyms Dictionary with Sound will get the job done. It is nonetheless lacking a number of things to make it a complete solution for your research needs.