The Friends of the Suffering Souls is a Catholic Lay Association which conducts a perpetual novena of Masses for the Holy Souls in Purgatory. It was inspired by the 100 consecutive Masses offered for the Holy Souls by the Venerable Archdeacon Cavanagh, Parish Priest of Knock prior to the appearance there of Our Blessed Mother in 1879.
The basic idea is that once a year, members ask a priest to say Mass for the Holy Souls. At the website you can read lots about why this is a good idea.
If you are a lay person, I encourage you to join the Association. If you are a priest, you may be able to help in a particular way. The Association needs priests who will be happy to accept requests for Masses for the Holy Souls. Unfortunately, I cannot put my name down because I have so many Masses already requested in my parish that I am unable to invite more from elsewhere. However I know that many priests do not receive many requests for Mass intentions. You can put your name down for the ordinary or extraordinary form, or both.
Email firstname.lastname@example.org to join or (if a priest) to make yourself available to accept requests for Masses. Priests are especially needed from the UK, Ireland, and New Zealand.