I have used internet banking for years now (mostly because we live in a country area with no shops and no bus service). I would not download anything to my phone though, as I am partially sighted and setting need to show fairly large print for me to read it, and I wouldn't want to use it in public, or when travelling.
Security seems pretty good, and I do get calls from my bank querying transactions from time to time. I check several times a week that all is well with my balance/transactions etc. and don't worry unduly about it.
Water Pollution -“ A National Disgrace”? A case for renationalisation?