Show HN: Umbrella – an open source digital and physical security handbook

Looks good, but one suggestion is to consider recommending GrapheneOS[0] over CopperheadOS on the Mobile Phone Alternative Firmware section. GrapheneOS is a continuation by the actual original developer[1] after the other party in the Copperhead project reportedly went a bit rouge.

[0] https://grapheneos.org/

[1] https://twitter.com/danielmicay

Initially built to help keep activists, journalists and NGO workers safe but relevant to a lot of people. Available in multiple languages and as a native iOS and Android App. More info: https://secfirst.org