Is this what you are talking about gsDroid?
"The easiest way, at least for me, to get an app into /system/app is to use
Root Explorer to copy the apk into /system/app.
To do this:
- In Root Explorer, copy the apk file you want to put in /system/app
- Navigate to the /system/app directory
- Tap the Mount R/W button on the top right
- Tap Paste
- Scroll down to the pasted apk, long press on it and select Permissions (you'll see 9 check boxes when you do this)
- Check the Read and Write buttons for User, and only the Read boxes next to Group and Others, then tap OK (once you're done, the read/write permissions under the app name should be the same as all the other apps listed (rw-r--r--))
- Reboot.
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