Spotify was developed as an open source app powered by the Spotify/Last.fm/Apple Music Web API. By choosing to use this app, you agree to the use of your Spotify account username and data for your top 10 tracks.
None of the data used by Receiptify is stored or collected and is not shared with any third parties. All information is used solely for displaying your Receipt.
Although you can rest assured that your data is not being stored or used maliciously, if you would like to revoke Receiptify's permissions, here is a guide for doing so.