When comparing Viber vs QKSMS, the Slant community recommends Viber for most people. In the question“What are the best messaging apps for Android?” Viber is ranked 8th while QKSMS is ranked 11th. The most important reason people chose Viber is:
Viber has native apps for both Windows and Mac that allow you to send and receive messages from your desktop. You can also use the desktop to make and receive calls. Synchronizes between all devices you are using Viber on. Allows transferring calls between devices.
Ranked in these QuestionsQuestion Ranking
Pro Desktop apps allow texting, calling and enables transferring calls between devices
Pro Supports voice calls
Viber has really well implemented voice tech. It has comparable quality to Skype and you can even tranfer calls from your phone to your desktop seamlessly.
Pro Completely free
Viber uses data connection and the app is free.
Pro Clean interface
The interface is simple, functional and intuitive.
Pro See who of your contacts is using Viber quickly
Viber is tied to your phone number so it can quickly see who else in your contacts list is using the application.
Pro Android Wear support
Viber includes Android Wear support on Android 4.3 or higher and Viber 5.3 or higher.
Pro Same protocol as used in Signal
Viber's protocol uses the same concepts of the "double ratchet" protocol used in Open Whisper Systems Signal application.
Pro Public chats
It's possible to be a fly on the wall on other group or one-to-one chats that have been opened up to the public. These public chats are often promotional chats with celebrities.
Pro Supports video calling over WiFi and data.
Can call friends using voice or video options.
Pro Combines cellular and data messaging
This has an advantage in that if you text someone who uses Viber it will be free, if not it will just revert to SMS. This means you can replace your standard messaging app with Viber as well.
Pro Keys only on device
Starting with Viber 6.0 the encryption keys are stored only on the clients themselves, not even Viber itself has access to them.
Pro No need to create an account or add contacts
One of the best things about Viber is how it handles setup and sending messages. Viber uses your existing number as your ID, so you don't need to create a separate Viber account.
Pro Supports 200 person group chat
Viber allows creating groups of up to 200 people on the Android version of Viber. It also has a cool "smart notifications" feature to prevent being overwhelmed with notifications if a lot of people are active in a chat group.
Pro Insight and well documented encryption
Viber has made a documentation available, explaining in great details their encryption system and giving good insight on how it works.
Pro Allows responding to SMS without opening the app
When a new sms is received, a window will pop up that has the message and allows answering it from there, without having to open the app. It can be dismissed by tapping anywhere else on the screen.
The app is available for free with an optional donation IAP that ranges from $1-$10.
Pro Per-conversation notification settings
Users can set different notification settings per user as an easy way to know who is messaging without having to look at the actual message.
Pro Readable in day or night due to themes
There are light and dark themes available within the settings which can be switched depending on how light it is around one when using the app. The dark theme can also help to conserve battery when being used as not as much brightness and hence battery will be used.
Pro Beautiful design
Responsive, highly customizable Material Design interface makes for a native looking app that fits in well with Google's UI design guidelines.
Pro Save yourself from sending out bad messages
Through delayed messaging one can set it up so that a message is not sent automatically. This can help for those times that it may be best to think something over before sending out a rash message.
Pro Very active developer who listens to the community
While QKSMS is one of the younger apps, the developer is quickly adding features/fixing bugs.
Pro Convenient Android Wear support
Those that own an Android Wear device will be able to set it to receive their messages on the Android Wear device making for convenient notifications and easy messaging through not having to take their phone out.
Pro Easily communicate with groups
Users can communicate with large groups at the same time due to the included group messaging feature. This is convenient when trying to synchronize with friends or colleagues.
Con No web client
You cannot login from the web to send and receive messages.
Con The company evades U. S. tax
The company uses the common practice of tax haven addresses in order to avoid paying US taxes despite being registered in Delaware.
Con Constantly on
Need apps like Greenify to stop it from being constantly on and active, even if you don't use it.
Con Constant reminders of messages
If you don't check your messages (say your in a group chat and simply don't check all of them), it will flood your notifications.
Con Doesn't sync well
Sync awfully between Phone and PC clients.
Con Proprietary Software
Not Open Source.
There are little annoyances here and there, from dark theme problems making text unreadable to crashing and missing notifications.