Some say that Paramamsa Yogananda 're-introduced' Kriya Yoga...

Yoganandaji was representing a lineage of teachers and was passing on a set of practices that had already been 'introduced' by them.

Being probably the most well-known Yogi in the West, it could be said that he introduced Kriya Yoga to the West.

Yogananda also made some adaptations to some of the Kriyas for Westerners as he felt that there was a difficulty for them to practice the original forms.

So, it would perhaps be more correct to say that Babaji reintroduced a specific set of Kriya Yoga practices through Lahiri Mahasaya (who was Yogananda's teacher's teacher).

Since then, there have been many Kriya teachers and schools that have come down from this lineage that began with Lahiri Mahasaya.

Paramahamsa Yogananda is perhaps still the most well-known representative of the Kriya teachings, due to his best-selling book 'Autobiography of a Yogi' and the organisation that he founded - the 'Self-Realization Fellowship' (or 'SRF').

Kriya Yoga practices are also taught by others teachers and lineages, although some of them may not call the practices 'Kriya Yoga'. 

For example Swami Sivananda's student Swami Satyananda Saraswati has taught and authored books that explain many Kriya techniques - these being in fact common to many Kundalini Yoga and Tantra practices.