I have discussed the problems of reversing a Flutter-based app in this 2021 post: Reverse Engineering a Flutter app by recompiling Flutter Engine. Some app checks their signature, and repacking APK will change the signature (usually, I will resort to in-memory patching with Frida) It takes quite some time to extract APKs from a device, reflutter, re-sign, remove the app, and reinstall the new one If we need to compare the unpatched and patched binary, we need to reinstallt he app Assuming that we have a replacement flutter library available (downloaded from the release page of reFlutter), we can hook android_dlopen_ext using pltHookRegister (a Zygisk API) and pass in the new library.