When comparing invi vs Signal, the Slant community recommends Signal for most people. In the question“What are the best SMS apps for Android?” Signal is ranked 3rd while invi is ranked 9th. The most important reason people chose Signal is:
Signal uses an advanced end to end encryption protocol that provides privacy for every message every time.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Automatically switches between SMS and IM
invi automatically detects if you're talking to someone who's on invi, and switches between SMS and IM automatically to accommodate. That way, you get fully-featured chats when you're talking to someone who has invi, but you also get a beautiful, seamless experience when simply sending SMS messages.
Pro Share and consume rich media without leaving the app
The killer feature of invi is the ability to consume media in the app. For example if someone sends you a link to a Youtube video invi automatically turns it into a playable widget.
Not only can you view the media in the app, but you can also discuss the videos, photos etc while they are playing.
Pro Beautiful interface
The apps design has a level of care and detail put into it that is rare on Android apps. The home screen is not only beautiful, but shows useful information such as the last message sent, and the status of the person.
The messaging interface itself is very clean and useful. As well as the conversation history it tells you if the recipient has read your last message, is currently reading the conversation or is replying. This makes conversations in invi very fluid as you always know the status of the recipient.
Pro Makes it easy and fun to share stuff
invi makes sharing easy and fun - great to enrich conversations with stuff like YouTube clips, photos, games, web articles etc.
Pro Uses phone numbers for contacts
Invi uses your contacts phone numbers, not a app specific username or email address. This has pros and cons. On the upside it's very simple to get started as it automatically adds all your contacts who have invi installed, and if you text someone who doesn't have invi it will simply go to their normal inbox. This makes it very easy to integrate invi into your existing workflow.
On the downside you cannot chat to someone if you don't have their number (gchat friends for example).
Pro Certain apps can be used in split screen
A collection of apps can be used in split screen view with the messenger. These are apps designed or ported specifically for invi. Some of the apps included allow browsing sites like reddit, 9gag, buzzfeed or playing games like 2048 while using the app.
Pro Provides security and privacy
Signal uses an advanced end to end encryption protocol that provides privacy for every message every time.
Pro Free and open source
Signal is free and open source software, enabling anyone to verify its security by auditing the code. It's the only private messenger that uses open source, peer-reviewed cryptographic protocols to keep your messages safe.
Pro Supports encrypted group chats
Pro Has a desktop app
Signal Desktop can be used on multiple devices and has most features of the Android version, although it still requires you to register with your phone.
Pro Supports sharing of various different media types
Signal supports: emoji, pictures, videos, audio, contacts, any location and GIF.
Pro Note to Self feature
Allows you to "send: messages to yourself and sync to desktop so you can use Signal as a kind of encrypted Pushbullet alternative
Pro You can easily view all media exchanged
You can easily view all media shared in the chat without scrolling back to when it was shared.
Pro Annonymous Sender (Encrypted)
The sender credentials can be encrypted with the rest of the message, leaving only the recipient address readable by the Signal server. Even if Signal wanted they couldn't see who is talking with who by this mean.
Pro Works everywhere in every country
Unlike most messenger apps, Signal works reliably in all countries by securely circumventing internet censorship.
Pro Recommended by Edward Snowden
Edward Snowden uses this messenger and recommends it to everyone who is concerned about his privacy.
Cons
Con No group chat
Con You can only search contacts and not messages
Con Early in development
This app still has some rough edges and missing features (like group chat).
Con Registration difficult for those without a phone #
For those that do not want to share their phone number or just do not have one to share, registration for invi can not be done. This means the app cannot be registered on a tablet or media device (like an iPOD touch) unless there is a number to give, of which neither of those devices when used by themselves have.
Con Android only
The many features cannot be used with people who aren't on Android, and you cannot login from the web.
Con Needs access to your phone number and contacts to work
Con Single device
Signal can only be registered to one mobile device at a time. But you can link Signal to Signal Desktop.
Con Servers hosted in the US
A security risk due to National Security letters, which require giving up data to the US state, and making it illegal to disclose that.
Con Unreliable notifications
Sometimes messages won't be received if the Signal app has been closed for a long time or hasn't been opened after booting the device.