--- title: "Sign unsigned builds" sidebar_position: 4 --- Mattermost publishes an unsigned build of the mobile app in the [GitHub Releases](https://github.com/mattermost/mattermost-mobile/releases) page with every version that gets released. These unsigned builds cannot be distributed nor installed directly on devices until they are properly signed. --- Android and Apple require all apps to be digitally signed with a certificate before they can be installed. --- To avoid rebuilding the apps from scratch, you could just **sign** the unsigned builds published by Mattermost with your certificates and keys. - [Sign Unsigned Android](/developers/contribute/more-info/mobile/unsigned/android) - [Sign Unsigned iOS](/developers/contribute/more-info/mobile/unsigned/ios)