Permanent Variable or ID by App Instance

[BRFT]

I have an app that is used on two devices.  Both devices are signed in with the same service account.  The app sends an email to a users as part of its operation.  I would like a way for the app to identify which device sent the email.  Is there a way to set a permanent variable on a per-device basis, or get some kind of unique device ID?  Anything that is different between the two devices could be used.  (note both are connected to the same Wi-Fi network) I would like to avoid either having two copies of the app or creating a step that must be performed every time the app is used (e.g., clicking a button on start-up).

[Pstork1]

Variable information is only maintained while an app is running.  There are no permanent variables.  There also is no function at this point for obtaining device information. There are a couple workarounds that you could do.

1) Do a SaveAs on the Completed App to make a second copy.  Add some variable in the startup of each copy that would uniquely identify that running instance.

2) If one of the devices is a mobile device and the other is a desktop you can use some of the functions that only work on mobile to tell the difference between the two devices. Here's a video on how. #PowerApps Check if user is on Mobile or Desktop - YouTube

There is also a Feature request to add a Device Info function.  You might want to vote that up. (3) Get Device Info in PowerApps - Page 2 - Power Platform Community (microsoft.com)

[timl · Accepted solution]

@BRFT 

In addition to what @Pstork1  says, here are a couple of other suggestions:

3) If this is a web app, you can append a different parameter value to the URL and start the app by using a bookmark that contains the parameter value. You can call the Param function to retrieve this value from your app.

4) If this is a mobile app, you can create an admin screen that sets a variable and you can persist this value onto the device by calling the SaveData function. This would be a one-off step that you would carry out on each device. On the start of the app, you can call the LoadData function in the OnStart of your app to load the persisted value.

[BRFT]

@timl I used option number 4 and it worked perfectly (SaveData/LoadData) There was an error message (error with data load, or similar) the first time the app was opened on mobile, but from there, it worked as designed.