HeyWire - FREE Texting is a messaging service that lets you send free text messages to any phone, regardless of the mobile operator.
Functions:
It lets you send messages to any phone through the Twitter and HeyWire websites; provides a photo editor and a memes generator, records and sends voice messages.
How to use:
You have to register your phone number and fill out a form with personal information on the HeyWire site, which is then sent account acces information. You can customize the settings and change the password if necessary. The last step is to insert the contacts. Don't forget your country code.