Looks and sounds like a variety of lemon, to me. My lemon leaves smell of scented lemon when rubbed and they have the pink/purple blossoms when in bud. Very pretty.

To my knowledge, it is definitely a type of lemon, but I have no idea what type. Most lemons produce purple flowers. What is the story on this tree?

If I were to guess my guess would be Meyers Lemon, but it is only a guess

It is a sour fruit.. Most probably a lemon or lemon hybrid but it could be a citron or sour limetta.

Definitely some sort of lemon.

Not a Meyers, it looks like my Eureka lemon tree with prominent pink purple flowers.

It looks exactly like my Eureka lemon did.

I did a little research on this variety of true lemon (unlike the Meyer's which is a hybrid..., not that there is anything wrong with that), it seems to be somewhat more cold sensitive than say for example, the Lisbon. It also is much less thorny and blooms more freely throughout the year. I have the Eureka, Lisbon, Meyer's and Ponderosa (another hybrid btw). I have found both Lisbon and Eureka to be reliable growers but of the two, Eureka really seems very vigorous and larger in scale (so may be more of a concern in a container). All of mine will be getting some lovin' this weekend as they finally are moved outside.