When comparing ChatSecure + Orbot vs Delta Chat, the Slant community recommends Delta Chat for most people. In the question“What are the best cross-platform encrypted messaging apps?” Delta Chat is ranked 5th while ChatSecure + Orbot is ranked 10th.
Ranked in these QuestionsQuestion Ranking
Pros
Pro Passed EFF's security review
To pass EFF's security review ChatSecure had to encrypt data in transit, the encryption had to be end-to-end, the app needed to provide forward secrecy, app's source code has to be open to independent review, users have to be able to verify contact's identities even with the service provider compromised, app's cryptographic design has to be well documented and app's source code has to have been audited in the last 12 months.
Pro Free and open source
ChatSecure is free and open source, enabling anyone to verify its security by auditing the code.
Pro Works with popular chat services across mobile and PC
ChatSecure works with Google Hangouts, Facebook messaging, Jabber and other popular messaging service, making for a convenient way to use secure chatting.
Pro No phone number required
Pro Open Source
Pro No registration required
Pro PGP-encrypted via Autocrypt Guideline
Pro Uses well-established protocols
Everyone knows/uses Email.
Pro Distributed architecture
There is no central Delta Chat server.
Pro You can forward a message from one chat to another
Pro You can share a document, a file, an image, an audio even with applications outside Delta Chat
Pro Multi account
Pro Disappearing messages
It has messages that disappear automatically.
Pro Independent video chat
You can use Jitsi Meet or other providers.
Pro You can reply privately
When you are in a group and want to comment privately on a person's sentence, press and hold on the sentence and click on reply privately. The user will be notified with the quoted and commented sentence. If he clicks on the quoted sentence it will take him to the group and to the position where he wrote this sentence.
Pro You can create broadcast lists
It will be present in the next version.
Pro Bots can be created
Without needing to have a space on a server, just a simple PC and an email for the bot.
Pro You can send stickers and animated stickers
Pro You can decide to set a limit for the size of messages that will be downloaded automatically
Pro You can set a ringtone for each chat
Cons
Con Email providers "recipents" per day limitation
Unless you control or run your own email server.