Sprive - mortgage overpayment. Can anyone explain it please?

[Whatliesbeneath707]

I keep seeing this Sprive thing advertised but you have to download the app to get the info, I think.
Is anyone using it to overpay their mortgage & would you recommend it? I'm not sure how it works - can you explain it to me, please?
Thank you.

There’s a FAQ page, calculators etc. No need to download.
https://sprive.com/faq/

You earn cashback on your shopping and it goes towards your mortgage or you can withdraw to your bank. There’s a sign up bonus if you sign up using someone’s link too.