Say Hi! Alternatives

WhatsApp Messenger: More than 1 billion people in over 180 countries use WhatsApp to stay in touch with friends and family, anytime and anywhere.

free

Chat for distributed teams. Zulip combines the immediacy of real-time chat with an email threading model. With Zulip, you can catch up on important conversations while ignoring irrelevant ones.

Fast, simple & secure messaging. Privacy that fits in your pocket.

Handcent SMS is a free enhanced SMS and MMS application for Android.

QKSMS is a beautiful communication app that offers magical texting experience.

Android Messages is a world’s most leading communication app by Google for Android device.

Vocaroo is a quick and easy way to share voice messages over the interwebs.

chompSMS is a communication app developed and published by Delicious for Android and iOS devices.

Telegram is a messaging app with a focus on speed and security. It’s superfast, simple and free.

Clyp is the easiest way to record, upload and share audio. No account required.

Dasher lets you do more than just text message. It's messaging with benefits:

Open source interoperable collaboration app.

Send messages, files, create groups and make Tox to Tox audio and video calls. Securely.