How to install newer test version of my installed android app without uninstalling it?

Question

I have my application in Google Play, I've downloaded and installed it on my phone. I'm also currently working on update of this application, and whenever I want to install my .apk file on my phone it shows me, that I can't do it, because the app is already here.

Where in Eclipse can I set some settings, which will allow me to install my updated app without installing original one?

EDIT

I want to have two versions on my device at the same time.

Answer 1

One simple solution is to change the package name, since that's how the OS identifies the .apk. Indeed, the package is unique to the Market: how does an android phone(or market) recognize an app

Answer 2

You can not install and run the app from eclipse because the app installed on the device (the one from play store) is signed with a different key.

When you export your app you sign the apk with a specific key and when u run it from eclipse you sign it with a different key - the debugkey.

If you HAVE to install another version on the device without uninstalling the old one from the device (the one you got from the play store) you should:

1.export your app and sign it with the same key you signed the app you uploaded to the play store.

2.upload the exported apk to the device.

3.install it.

EDIT: If you want to versions on the same device you should change the app package name.