I find myself needing to change DNS servers from time to time on my unrooted Android 6.0 Tablet.

I tried doing this just through settings but I keep getting "Unfortunately Settings app has stopped" before I can apply any changes.

I see in Play Store that there are apps for doing this and I downloaded one which worked first time I used it, but now it is asking me to do ratings before letting me use it again.

I object to this type of behaviour.

I am happy to pay for an provided that app is ad free and does its job without being obnoxious.

So I was wondering if anyone here is using such an app, free or paid, that they are happy to recommend.