I know that memorising the whole the Quran is fard kifaya but are there any other fard kifaya acts ?
The most known examples are the funeral prayer (salat al-Janazah beside the janazah -burying itself- and the ghusl of the dead person), jihad, memorizing quran, getting or seeking knowledge, enjoining what is good and forbidding what is evil and ijtihad.
What constitutes fard al-kifaya فرض كفاية is that it is an obligation on the Ummah, but if any of them perform this obligation the rest would be exempt from performing it, but if nobody does it the Ummah would be considered as sinning.
قال الإمام الشافعي رحمه الله : "حق على الناس غسل الميت ، والصلاة عليه ودفنه ، لا يسع عامتهم تركه. وإذا قام به من فيه كفاية أجزأ عنهم ، إن شاء الله تعالى" انتهى من "الأم" (source islamqa#131270)
Al-Imam a-Shafi'i has written in his al-Umm: "a right people must fulfill is washing the dead, praying on him and burying him, and they can't leave it all of them, if enough people did it those would be rewarded and the rest exempt from it, if Allah wills"
But a fard kifaya can easily move from this state to the state of fard 'ayn فرض عين, an obligation which must be performed by anybody (except people who have special conditions).
For example if Muslims don't have their own physicians anybody would be asked to learn this science until we would have a capable person, if nobody re-reads the sources and does ijtihad we are all asked to do so until we find at least one capable person.
And for jihad it is fard kifaya for jihad to attack the enemy (if this is an allowed option) or help oppressed Muslims in a place far away, but if the enemy is in your country it would be fard 'ayn to fight him!