Specification of app features for comparison with other security focused messengers

[ghost]

Here is the full list of uncompleted questions in this comparison, which currently does not include CoyIM. I was able to fill out some of them already. It would be great to hear from you guys and get some answers.

About the app
Price: free
Repository: GitHub
Software license: GPLv3
Availability: GitHub
Client is available since: 2015?
Comes without proprietary libraries:

Platforms
Available on Android: No
Available on iOS: No
Available on Windows: Yes
Available on macOS: Yes
Available on Linux: Yes
Available via web client: No

Privacy / Security / Anonymity
Encryption protocol / library: OTR 3
Cryptographic primitives:
End-to-end encryption: Yes
End-to-end encrypted 2-user chat: Yes
End-to-end encrypted group chat:
E2EE is turned on by default:
Local message encryption:
Perfect forward secrecy is enforced:
Certificate pinning is used:
Directory service can be modified to enable a MITM attack:
Contact verification possible:
Contact can be added without needing to trust a directory server:
Notification if contact's fingerprint changes:
Contact's fingerprints can be verified manually: Yes
Avoids / Protects metadata during use: Yes via onion routing
Native Tor support: Yes (if installed)
Last security audit: -
Tracker integration (Exodus): No mobile app
Use without phone number possible: Yes
Use without Google Play Services possible: No mobile app
Reasonably useful without sharing the contact list: Yes

Ecosystem and developers
Centralized / Federated / Decentralized: Federated
Infrastructure hosting: Distributed server
Open Source server:
Transparency / Financing (Including donations):
Transparency report:
Legal jurisdiction:
Jurisdiction of the devs/company:
Funding:

Functionality
Visible if contacts are online:
Audio-/Video-chats:
Group chats:
Voice messages:
File exchange: Yes
Read receipts:
Editing sent messages:
Self-destructing messages:
Deleting sent messages locally:
Deleting sent messages for both (2 user chat):
Synchronization between multiple devices:

Backup
Storage location:
Automated:
Encrypted: