There are a number of different “Small Apps” available for Sony Xperia devices. However, a new one that has been launched by third-party developer “LuuTinh” relates to your SMS texts. The SMS Small App allows you to read and reply to text messages in a small window overlay.
SMS Small App can read/reply to five people on the same screen, it also allows you to directly call that person. The app’s background can also be customised. The app is currently free and available on the Google Play Store right now.