Hello 
,
AB Team
I am here with new bug report
When I am open AB Builder in mobile and try a simple project when I go to block option the topbar is dispear than we need to reload page than go to Deigner section
Try to fix as soon as possible 
Your paithful user,
Silktune
I think Android Builder is made for Desktop version, I am not sure but it was great to here that Android Builder can be run in android browser.