People have been waiting for the 5th volume of the
Philokalia to be published in English for many, many years, but a presumably unpolished English text was published as part of a bi-lingual (
Malayalam / English) edition in India in 2006. Tikhon Pino has made a copy of the text available on his Academia site, which can be downloaded here:
https://www.academia.edu/40333540/Philokalia_Vol._5_Kallistos_and_Ignatios_On_the_Life_of_Stillness_English_
Update: Tikhon has the full text in hard copy, but what he has posted is about a third of the total of that volume. It is the full text of the Chapters of Kallistos and Ignatios.