When comparing StealthChat vs Google Allo, the Slant community recommends StealthChat for most people. In the question“What are the best messaging apps for Android?” StealthChat is ranked 17th while Google Allo is ranked 22nd. The most important reason people chose StealthChat is:
Messages can be set to self-destruct after a set time.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Can send self-destructing messages
Messages can be set to self-destruct after a set time.
Pro Offers 3 types of encryption
The app claims to be the only communication app that encrypts data in transit, on disk and on screen. Encryption in transit is used to make sure no-one can listen in on your conversations even if the traffic is going through their servers, encryption on disk is used to make sure that even if someone gets ahold of your phone and is capable of extracting your messages from it they won't be able to read them and screen encryption is essentially a lock screen that sets in after a set amount of time used to make prevent "shoulder surfing".
Pro Integrated with Google Assistant
Automatically shows options for restaurants/movies/etc when relevant according to the context of the conversation. It's also able to perform actions accordingly like order tickets.
Pro Supports end to end encryption
You can send end to end encrypted message that will auto-delete themselves after a specified time.
Pro whisper SHOUT let's you express yourself through text size
You can easily adjust the text size to show either a whisper or a shout, adding emphasis to your messages. Simply hold the send button and slide up (to shout) or down (to whisper).
Pro Message can self-destruct after a certain time
You can send end to end encrypted message that will auto-delete themselves after a specified time.
Pro Animated stickers and emoji
Some shouted emoji animate and you can download additional stickers and send animated stickers.
Pro Full resolution picture sharing
Pro Smart replies
Part of the Google Assistant is providing common answers based on your conversation thread (like in Gmail/Inbox).
Pro Themes
Each chat's theme can be changed to one of a few themes. Some themes even have specific chat colours for each user, making it easy to see who is talking.
Pro Can share a location
Share your current location or any place with other people.
Pro Encryption on-the-wire and in cloud storage
All messages are encrypted while in transit and on Google's servers.
Pro File sharing
Cons
Con Many people have difficulty registering the app
Multiple people have reported not being able to receive the activation code required to register the app.
Con Code is not verified
Con Poor support
Con Lacks group chat
Con Closed source
No way to verify security practices.
Con No web interface (yet)
Currently there is no web interface to send message using your computer. Project leads have teased screen shots of the web interface.
Con Few users currently
Allo was just released in September, 2016 and it doesn't have a very large following yet. We haven't yet seen how popular it's going to be.
Con Exclusive
If your contacts aren't on Allo it is worthless, and no one is on Allo. Tried it after Hangouts fail, discarded it within days.
Con History deletes on sign in
If you uninstall the app or migrate to a new phone your messages history is deleted. This, despite the fact that Google keeps a copy of your messages permanently for data crunching.
Con Single device
Part of reliably saying if one saw your message, and having it tied to a phone number, is that you cannot have the same Allo account on two phones.