I use Monzo Flex to spread larger purchases over 3 pay periods. Works great and is fully integrated into the bank which is good.
I have used Klarna on occasion for their pay in 30 product. Just to try clothes and return them (it needed) without having to mess around waiting for refunds.
I’ve used Tymit a couple of times to spread payments. Mainly deposits.
I tried klarna as I thought it could be handy for a couple of larger purchases, but my Barclaycard just declined all attempts and I really don’t like the weird virtual card per payment nonsense, so gave up on them straight away.
Overall, it just adds a layer of complexity, with the Tymit approach being the last complex (pay by card, then spread payments) through to klarna that wants all your data and needs you to create virtual cards on advance, plus minimum transaction amounts Eugh
Looking at the apps themselves, the whole story is about pushing wildly overpriced tat as some sort of lifestyle product. Shop is the same thing. Unless you have a very specific use case and or retailer with this that you already love, steer clear, imo
I’ve never used the likes of Klarna or other such apps, not sure I see any reason to either.
Many years ago I bought a laptop on a 12 months interest free deal from Very, I think there might have been another couple of times they gave me offers to use my credit account (although I’m pretty sure I cleared the balance in full straight away each time - it’s been a very long time since my account closed due to inactivity).
Many years ago I also bought some sofas on a Creation 4 year interest free loan.