A friend has drawn my attention to this new initiative from the Latin Mass Society, which I shall sign up to - I am copying the LMS website piece about it:
THE LMS SODALITY OF ST AUGUSTINE OF HIPPO
"...pro se orare necessitas cogit, pro altero autem, caritas
fraternitatis hortatur. Dulcior autem ante Deum est oratio, non quam
necessitas transmittit, sed quam caritas fraternitatis commendat."
"Necessity makes us pray for ourselves, fraternal charity urges
us to pray for others. But sweeter before God is prayer which is not
sent from necessity, but commended by fraternal charity."
Summa Theologica II, Q88 a.7 c. (St Thomas Aquinas)

Introduction
The purpose of the Sodality is to
unite the prayers of members for the conversion of those dear to them.
There can be few Catholics today who do not have family members or close
friends who have either lapsed from the practice of the Faith, or never
had it; it is a particular source of grief when parents see children
and grandchildren living without the support of the Sacraments. We take
heart from the example of St Augustine, converted at last by the prayers
and tears of his mother St Monica, and wish to demonstrate our
fellowship with others in the same position, by praying not only for our
own dear ones, but for those of others who will do the same for ours.
Duties of Sodality Members
Sodality members
undertake to say every day the prayer Pro devotis amicis, taken from the
Roman Missal, for the Sodality’s intention; members who are priests
undertake to say one Mass a month for this intention. The intention is
the conversion or return to the Faith of family and friends of Sodality
members. The intended beneficiaries of our prayers are not listed,
except in the hearts of Sodality members. The Latin Mass Society, to
which the Sodality is affiliated, will arrange and announce in advance
at least one public, Traditional Sung (or Solemn) Mass for the
Sodality’s intentions a year. Please note that the undertaking, by
members, to pray for the conversion of others does
not bind under pain of sin.
Additional ways in which Sodality Members can help the Apostolate
Sodality
members, both lay and clerical, may add other Masses, prayers, and
devotions, for the Sodality’s intention, and are encouraged to do so. In
particular, members will be asked annually if they wish to make a
contribution to the costs of the Sodality’s public Mass or Masses, and
whether they would like to make a Mass offering for an additional Mass
or Masses to be said for the Sodality’s intention, which the Latin Mass
Society will arrange, to be celebrated according to the Extraordinary
Form. (The customary Mass Offering is £10.)
You can make an offering towards an annual Mass or towards an additional Mass at
the bottom of this page.
Joining the Sodality
Membership of the Sodality is free and open to all; members sign up by
email.
Please provide your name, address, email address, and phone number. (It
would help us if you would inform us of any
change in your contact
details so that we can continue to inform you about Masses offered for the intentions of the Sodality.)
The Sodality Prayer
Pro devotis amicis (which may be said in Latin or any other language):
Deus, qui caritátis dona per grátiam Sancti Spíritus tuórum
fidélium córdibus infudísti : da fámulis et famulábus tuis, pro quibus
tuam deprecámur cleméntiam, salútem mentis et córporis ; ut te tota
virtúte díligant, et quæ tibi plácita sunt, tota dilectióne perfíciant.
Per Dóminum nostrum Iesum Christum Fílium tuum, qui tecum vivit et
regnat in unitáte eiúsdem Spíritus Sancti, Deus, per ómnia saecula
sæculórum. Amen.
O God, who, by the grace of the Holy Ghost, hast poured the
gifts of charity in the hearts of thy faithful, grant to thy servants
and handmaids, for whom we entreat thy mercy, health of mind and body;
that they may love thee with all their strength and, by perfect love,
may do what is pleasing to thee. Through our Lord Jesus Christ thy Son,
who liveth and reigneth in the unity of the same Holy Ghost, God, world
without end. Amen.
Masses for the intention of the Sodality should include, when
possible, the Commemoration ‘Pro Devotis Amicis’ (Collect, Secret and
Postcommunion) found in the Roman Missal. Adding such a Commemoration is
possible in the 1962 Missal on Fourth Class Feasts at Low Mass, where
no more than one Commemoration is demanded by the Ordo.