Test on one iPhone, and one Android.
On master site, navigate to Database testing course.
Enter database named: "New database using all field types English" on section "More databases" .
Add a new entry.
Edit the first field field named "A checkbox field name (required): " by clicking on the Choose select.
A new alert would open.
Rotate the phone to landscape.
Check you can scroll the options and you can see Ok and Cancel buttons and it's all usable.