The only reason I stick with Tandem is because of the 0.5% cash back and the instant notifications. Nothing else about the company, and their app, is revolutionary. The UI is basic to say the least and the customer service response times are archaic.
I tried their auto-savings round-up feature for a few weeks but found it poor due to a poor savings rate (0.5%), and that the round-up collections didn’t actually tell you what transactions it had rounded up.
Overall, once I identify a credit card that offers the same/better cash back, instant notifications and a better user experience them I’m jumping ship.
If you sign up to Tandem using my Referral Link we both receive a £10 Amazon voucher.