The most famous example can be found at the bottom of this page: https://www.alphadictionary.com/fun/tongue-twisters/swedish_...
å: stream
ö: island
i: in
ä: not correct, but used to represent dialectical pronunciation of "är", i.e. "is"
But that only has "...e å, å i åa ä e ö" -- not the bit about "å i öa ä e å" from that tongue-twisters page, which seems to be a later addition. Ungrammatical, too: I'm sure even värmlänningar would say "på öa", not "i öa".
(Oh, and "e" is of course a contraction of the indeterminate article "en", a/an.)