The issue with "invisible" text affects mostly Android 6 and 7 users. It can't be fixed via update because signing key is lost due to PC virus infection. New app is on the way, link will be posted here. Thank you all for your reviews and patience!
It's secure to download this application. AlcaSoft is the developer of the app that can be found in the Personalization category. According to the latest information, Minimal RED XPERIA Theme is rated 3.2 on Google Play.
This application has been downloaded and set up by over 10K users and the latest update was released on Jun 13, 2016. It's free of charge to download the installer of Minimal RED XPERIA Theme, also, you can take a look at users' reviews on Droid Informer. The app works fine on Android 4.4 and higher.