ttmsg

ttmsg is a messaging app based on MQTT, a publish-subscribe protocol.

Introduction to MQTT, including architecture diagram can be found here and protocol specification is found from OASIS site: http://docs.oasis-open.org/mqtt/mqtt/v3.1.1/mqtt-v3.1.1.html. MQTT Essentials is also a good reading.

Web site mqtt.org describes protocol as: "a machine-to-machine (M2M)/"Internet of Things" connectivity protocol", but nothing prevents using MQTT on human-to-human messaging and that's the main use case of ttmsg-app. The other use case is human-to-machine messaging.

Publishing, or sending, messages is simple. MQTT client, ttmsg-app in this case, connects to a broker and publishe message to a topic. Topic can be a string, such as "helloworld". In order to receive messages, client needs to subscribe to the topic. After subscribing all messages that are sent to a topic are received. This also means that if client is not subscribed to a topic, nothing is received.

Help video

See this video that briefly shows how to use ttmsg: https://youtu.be/r5KmaNiHqhU.

The app is simple to use and in the video, you see it too. You see how to publish messages, how to subscribe to topics, how to publish images and see the settings page.

Real life example

You and your friend meet and talk. Perhaps in a physical place.
You decide that you want to communicate with each other, without others knowing or finding out.
You choose a topic name, a password and time when you communicate.
At the chosen time, you open ttmsg-app and send encrypted message to a topic.
As agreed, your friend has subscribed to a chosen topic and receives your encrypted message.
You communicate, until you close the app.
There is no record of your communication in your devices.

Features, including Premium

No registration.
No authentication.
No saving of messages. Not on app and not on broker.
No messages received when not using ttmsg. No notifications of any kind.
No knowing if anyone is receiving messages.
Multiple publicly available 3rd party brokers:
Set a custom MQTT broker. Use other public broker or install your own (recommended).
Send images to a topic. They are not saved anywhere.
Encrypt messages using custom password.
- Encryption uses DES-algorithm in order to avoid United States government encryption registration requirements.
Passwords can be set for each subscribed topic.
UI based on text-based command line interface.
Many open source libraries are used in ttmsg: 3rd party libs.

Flagging and Blocking

App Store Review Guidelines includes section 1.2 User Generated Content. ttmsg includes flag- and block-commands which are implemented to comply with guidelines. Block-command enables user to block content so that similar content and content from same publisher is no longer received (limited to topic). Flag-command enables users to flag messages so they are no longer received in any topic, and it also sends a command message to block the user (who sent the flagged message) from sending messages to the topic.

Contact

Questions, feature requests, etc.? Contact me.

Other apps

Command Line Program
Gravity One
Tycoon One