Farewill is not a charity, nor a law firm. Charities pay the will writers to participate in the scheme in the hope of getting substantial bequests. The will writers push the client in to making them executors so they can make more money.
Farewill also sells direct to crem funerals.
Martin Lewis says:
"Many charities offer fee-free will-writing by solicitors. In return, they hope you'll make a donation or leave a 'bequest' in your will (leaving them something when you die) – though you're not obliged to.
Do remember though: it is a charity paying for your will, and it may be shelling out £100s, so please seriously consider leaving a bequest."
https://www.moneysavingexpert.com/family/free-cheap-wills/#needsolicitor