Mahsa
An android application which is designed to deliver safe and encrypted messages using SMS while Islamic republic of Iran banned Iranian people accessing to the internet. I designed and coded this project with one of my friends in Iran who described me lots of things happening in the Iran.
How it works
Mahsa, encrypts any message using AES256 with user defined key and sends it to the target. If the target has Mahsa installed on his/her phone, he/she will notify that a new encrypted message received. He/she should then enter the password to unlock the messages.
How to share passwords
Unfortunately while you don't have access to the internet, it's a bit hard to share passwords with others. You should share your passwords with people who you trust in the demonstration.
Where to use
When they banned accessing to the internet and you want to communicate with you friends to share locations of demonstration, you can use it to send ecnrypted messages. Don't forget that it's possible for them to track the people who use Mahsa (cause all of the messages will be base64 after encryption). You know what I'm saying: Use it when it's necessary.