You can sometimes find the latest .apk file directly on the developer's official site, strelokpro.online . Updating/Restoring on iOS (iPhone)
Updates are available via the Huawei AppGallery or by manually downloading APK files from verified sources.
If you already have the app and need the latest reticles or ballistics updates, here is the current game plan for 2025. How to Update Strelok Pro: The 2025 Survival Guide
Search for "Strelok Pro." You may need to repurchase the app (approximately €10) as it is a different platform.