I am using FBA authentication model into one of SP WebApplications in our SP 2013 farm to give users outside the AD, accessibility to one of SPSite so they can access the lists & Libraries and run sharepoint apps ..
for that I installed & configured the components necessary to enable & manage the FBA users easily by following the steps in the great article made by Sean Earp
Configuring SharePoint 2013 Forms-Based Authentication with SQLMemberShipProvider
Now I am able to acess my SPsite using FBA users and see the Libraries & Apps inside the SharePoint site. and when I try to access one of the provider-hosted apps, the request redirected to the remote web using the FBA account correctly, but I didn't have any access to web-app or host-app from the remote website.
Is there any restriction to access sharepoint-hosted apps using FBA authentication model in SharePoint 2013.
You need to made some entry in your remote IIS site's web.config file. Check below link. It might be helpful for you http://www.sharepointpals.com/post/How-to-create-a-Provider-Hosted-Application-on-Form-Based-Authentication-WebApplication-in-SharePoint-2013