[mrjabush]

Phone is Samsung Galaxy S5 Mini SM-G800F running Android 4.4.2

When I make an outgoing call, the phone app drops into a full screen with Call ended and duration plus icons for the person, phone, X to exit and SMS. The bottom half of the white screen has an ad. The example I have is for 8 Craft Beers.
If I touch the return key, or the X icon, the full screen end and returns to the phone app dialer.
This behaviour is new. It never used to do that. I'd like to figure out what is doing it and make it stop please!
I have a screenshot if needed and if someone can tell me how to upload?

[N4Newbie]

I'm not sure if this exists in your Android version, but in the Android Nougat developer's preview, you can go to Settings -> Apps -> [Gear icon] -> App permissions -> Phone to see what apps have permission to access phone data.

If not available in Android 4.4.2, you can probably find an app that will give you the same data. Just search the play store for "permissions".

[mrjabush]

Thanks for the hint re permissions. I suspected it was Touchpal. I installed Advanced Permissions Editor from the Play Store and found that it could see the phone status. I removed a couple of permissions as a test. APE essentially copied and edited the APK. A test call showed that the bad behaviour was fixed. Sadly, it also meant that two copies of Touchpal were running and worse, I had no keyboard at all!

[N4Newbie]

Interesting.

Looking at the user feedback for Touchpal at the Play Store, I see a number of complaints about obnoxious ads. One recent reply from the developer says:

TouchPal July 25, 2016
Dear user. Thanks for getting in touch. We do sincerely consider about your suggestion. Our appreciation will be shown in later version. Hope you can keep faith in us, we are growing to a better one for you.You can always subscribe to the TouchPal Premium to remove all the ads. I promise you that you will have a splendid typing experience. ^_^.

I'm not sure, but I think "Premium" costs $4.99. Ouch!