If you're still a heavy WhatsApp user, even after the whole sharing-data-with-Facebook debacle, do we have some good news for you. Freedom Pop, known for it's free and uber-cheap SIM deals, has just launched a new plan. For the low, low price of £0 a month, you can get 200MB of data, 100 minutes, and unlimited use of WhatsApp.
It's like having free unlimited texting, though slightly different because the messages are encrypted and all your data gets sent to Mark Zuckerberg's advertising friends. Also actual texting will cost you money.
It's worth mentioning that using WhatsApp does't use any of that 200MB data allowance, and it includes the app's voice calling feature. That should help those 100 minutes go a bit further. This deal has a global SIM as well, meaning you can use it in 30+ countries around the world without incurring any extra charges. The countries included are: the US, most of Europe, Bangladesh, Singapore, Indonesia, Malaysia, the Philippines, Thailand, and Vietnam.
Freedom Pop also has a premium WhatsApp deal on offer, which has unlimited WhatsApp, texts, and minutes, plus 1GB of data. That does cost £21 a month, which is pretty pricey, but there is a month's free trial you can exploit.
Obviously Freedom Pop is 'free' in that the basic deals have no set monthly charge. You still have to pay for things like activating your SIM, getting it posted to you, and voicemail privileges. You also get charged if you go over your meagre limits, so watch what you use.