logged in from friends tablet but in device manager it shows current device is my cell phone I logged into my Google account from my friends tablet.went to my account info page. Looked at  my recent activities and it shows all devices I've logged in from. The top one says My Cell Phones name and says  its my Current Device. HOW can that be? I'm across town from my cell phone at the moment and I'm on a friends tablet for the first time ever! Does this mean these two devices are linked in some weird way? Spy app or?? I can even go to google play and click on My Apps and it shows the apps that are actually  installed on my cell phone!
Apps you install from Google Play are linked with your account. This way, if you've paid for an app,  uninstall it and want to reinstall it again you can easily do so without paying twice.

If you have logged in to your friends tablet, this device is now connected to your Google Play account as well. It's a feature meant for when you buy a new  tablet. This means you can download all apps you have bought or installed on your previous (own) cell phone. Being able to see your installed apps is actually what's supposed to happen when logging into your Google account.

It's very strange that Google thinks you're currently on your cell phone while you're actually using a different device. Your friends tablet might have received the login token from your phone if you use the synchronisation features in Google Chrome, confusing their website.

It could also be possible that your device was doing something with your Google account (like updating apps) while you signed in.

Google can only really guess the exact device you're using when you log in to Google. Their current device indicator works most of the time but I wouldn't rely on it.

Try clearing the history, cookies and login sessions from your friends tablet or go incognito in Chrome and see if the website still says you're on your phone. There isn't any spy app active active and the indicator probably took a wrong guess on what device you were using.