apkdiffpatch
There are 2 repositories under apkdiffpatch topic.
sisong/UnityAndroidHotUpdate
I no longer install and use Unity3D. (Unity3D热更新。provide a way to hot update Unity app on Android, support code&resources, not need lua js or IL runtime etc..., will not disturb your project development; just loading the new version apk file to achieve. )
sisong/sfpatcher
stable & fast to patch apk archives, used by Android app store. 为安卓应用商店使用而优化的apk增量更新算法。