We'll be delegating distributing developer builds of apps signed by the developers to Accrescent rather than doing it in ourselves. Our App Store will be focused on our own apps and eventually hardened, rebranded builds of important third party apps widely used by our community.
GrapheneOS App Store now includes a mirror of Accrescent, which is a privacy and security focused alternative to the Play Store distributing developer builds of apps:
Accrescent comes from within the GrapheneOS community and we're collaborating together.
Accrescent is in alpha and isn't yet open to any developers uploading their apps. It will have a lot more apps available in the future. It will become a full alternative to Play Store permitting closed source apps too, but you'll be able to filter to show only open source apps.
Lead dev of Accrescent is a GrapheneOS user and contributor. It'll be a good place to publish apps for GrapheneOS users. AppVerifier, BeauTyXT and Transcribro are from the same person who wrote our Info app. Molly is a security-focused fork of Signal from another GrapheneOS user.
AppVerifier was based on a planned GrapheneOS feature for users to verify APK files based on their key fingerprint. The feature is currently stalled since relying on the clipboard isn't ideal. For now, users can use AppVerifier from Accrescent until we ship a built-in approach.
We'll be delegating distributing developer builds of apps signed by the developers to Accrescent rather than doing it in ourselves. Our App Store will be focused on our own apps and eventually hardened, rebranded builds of important third party apps widely used by our community.
AFAIK the main difference is that on F-Droid (at least the main repo), all apps are signed by F-Droid. On Accrescent however, each app is signed by its developer. This can be seen as it being more secure.
If you're further interested in the topic, there's at least one discussion thread about the 'insecurity of F-Droid', I believe also directly comparing it to Accrescent, on the GrapheneOS forum.
Accrescent is a store where developers can publish their software (will be able to, it's in alpha), just like F-Droid but more secure. It's trying to be an alternative to the Play Store.
Obtainium is a tool that can fetch and check the versions of APKs from different sources.
Accrescent has a list of apps that can be easily installed, unlike Obtainium, Accrescent doesn't require the user to spend a lot of time adding each app they want to auto update/install to Accrescent as the apps are aleeady there. Similar to playstore.
Obtainiums only advantage to me is that you can add almost any app source, while Accrescent still is in development and as such lacks lots of apps at the moment.