I assume you may be referring to one of the following:
Depending on the specific nature of Project Sister, the latest update often includes new assets, updated UI elements, or expanded story chapters. The developers have listened to user requests to make the interface more intuitive. How to Safely Install Project Sister QAAPK UPD project sister qaapk upd
Risk Management
If you enjoy Project Sister, research whether the original game exists on Steam, Itch.io, or Google Play. Many indie visual novels cost less than $10. Paying the original creator encourages more high-quality content. Fan projects should ideally be “original creations” (OC) or use open-source assets. I assume you may be referring to one