As we have announced earlier, we have discontinued the free plan in 3.x. We have written about it on our blog as well email newsletters. If your application was on the free plan in Backendless 3.x, you can either migrate it to Backendless 4 (which has a free plan and that is not going anywhere) or you can choose to upgrade the pricing plan in Backendless 3.x. To upgrade the pricing plan in 3.x, you need to:
If you have any questions, please contact us on the support forum.