Is there any simple way to protect the Android App and update it?

Question

I developed an Android App and installed to three users' cellphones through Eclipse and USB connection. I don't want to put the App to google market. Now I got two problems:

1. How to protect the App and make it invalid in other cellphones. I know we cannot protect it 100%, I just don't want the App to be easily copied and run on other devices. What I have done was hard coding in my program to compare the AndroidID (save the AndroidID to a string and compare with current AndroidID). The problem is that if I have 100 users, I have to hard code 100 times.

2. How can I keep the users updated. Do I just upload the updated App to my own server and give them the link to download and install? In this case, the first problem comes out again: how to protect the App?

Answer 1

我首先想到的是，您可以设置应用安装后首次运行该应用所需的密码，并将该密码仅提供给已启用的用户

Answer 2

you could make the application check for the presence of some pre-determined "key" file and distribute the file separately.

For updating the app can download new apk files and use an intent to send the user to the Package Installer so that they can choose whether or not to install.