Microsoft Forms, the solution to create web forms, is now available (or will be soon to those not yet enabled) for all Office 365 Enterprise plans.
Initially this was only available to Office 365 Education tenant.
To check if you are enabled, go to the Office 365 Admin portal to the Settings\Services & Add-ins section and check for Microsoft Forms
Then if you click on it you will be able to turn on/off (default is on) the functionality for external users
Finally you can now instruct your end-user to go to http://forms.microsoft.com/ to start using it and creating web forms.
This is not (yet?) available through the App Launcher but remember you can manually add apps to the app launcher from the Settings\Organization Profile section