The wills of English and Welsh soldiers who died in World War 1 are being made available, together with some letters that were judged by military censors as unsuitable to send at the time of their writing (because they disclosed too much).
There's a news story at the Guardian which says:
From Thursday [29 August] they will be available online, through a joint project by the storage firm [Iron Mountain] and Her Majesty's court and tribunal service: anyone can search the index by name, date or regimental number, and then pay a statutory £6 fee for a copy of any will. Iron Mountain has digitised everything in each record, so any letters, and the official envelopes recording the date and cause of death, will also be supplied.
The index is at https://www.gov.uk/probate-search, and includes English and Welsh soldiers "who died while serving in the British armed forces between 1850 and 1986". It does not include officers and Irish and Scottish soldiers.