Build a REST API for my existing android application

I would like to create a REST API for my existing application that allows users to add translations for any word. Example, a user searches for a word and once the result is shown, they can add a translation for another language. This would happen via a click and once that button is clicked, the user will be prompted to a new screen where they fill out the details: - word in new language -pronunciation of word. Once the user clicks is finished and presses enter, the change is saved and can be seen and accessed by anyone that searches for that word. I need to know all the details that are required for this to work properly, example, if a database is required, etc. A few more things. Once the changes have been made, an existing button will show the user what translations are available and what language the translation is from. If no translation exists, then a message will appear informing the user that no translation exists. There should also be an option for the translator to record and save their audio and play it remotely.