Irritating. I paid for it on my Nexus sometime back, but keep getting a -504 error when trying to upgrade. Just for the heck of it, I purchased a copy for my cell phone, to see if it had the same problem. It does. The older version was nice, but the upgrades are worthless. I'll unsubscribe both versions, and find a better math drill package.
Helpful :) Good for practice but hope that you can include instructions on how to solve it...
A good challenge
Not allowing me to use the pro Paid the money for the pro version, but won't allow me to use it. Keeps saying "Error, authentication required. You have to sign into your Google account", even though I am already logged into my account. Fix or refund me. Thank you
▶ new chapter "Mixed 2"
▶ performance improvements and finer animations
▶ more supported display sizes