I used shapeshift in 2016/2017 with changelly through my wallet app called coinomi and they both works like same but now KYC is a must for shapeshift so if you are looking for an alternative changelly is the best, its old too around same time with shapeshift
You have to be careful about Changelly though. I have seen complaints on reddit where they have held held user funds until they complete KYC verification especially when their transactions are labelled as "suspicious"
You can use it but know that anytime the lock up your funds, you must be ready to complete KYC verification to have a chance of getting the funds back.
I've used changelly for small amount of swaps before but I don't really recommend that to others as I know the risk that it has. I agree that a person who would like to try them must be very careful if they're going to use them but if there's a better option like fixedfloat then that's a better swap to use.
Thanks to list above, I might start using fixedfloat.