In a BBC interview via texting, Matti Makkonen discusses the birth and growth of SMS and how he shouldn't be considered its creator.
The charges come a month after T-Mobile unveiled a program to offer refunds to customers hit by premium text messages. T-Mobile calls the charges "unfounded."
The latest Facebook Messenger update lets you "Like" things even more emphatically, as well as recording 15-second video messages right there in the app.
With a jump of more than 40 million monthly active users since the end of 2013, the mobile messaging app's star appears to be on the rise.
The site also promises to keep an eye out for suspicious log-ins and may ask you for further information to verify your account.
Samsung ChatOn version 3.5 lets you delete messages even after they've been read, as well as adding new location, language and file-sharing features.
Set your email app to forward messages from a particular sender to your phone's SMS address automatically.
You can send text messages to anyone using Terminal.
The NSA is able to extract data including location, contacts, and credit card details from a massive database of global SMS messages, reports The Guardian.
Experts say WhatsApp and the like contributed to the number of text messages sent falling for the first time last year.