Every Ubidots for Education user received 5,000 free credits to begin a project. After these credits have expired, users may top-up 1,000 credits to their account for a mere $5 per charge.
Ubidots for Education credits will trickle away from any account based on the below schedule:
This means that, depending on the size of your project, you can run cloud solutions on Ubidots for Education free forever (first device is free forever in Ubidots for Education) or pay a few dollars as you go to keep you developments and experiments live on the cloud.
For more information, see the following guide: