Here is 3 recommendations for forum creation apps.
1. Flarum
Flarum is a simple discussion platform for your website. It's fast and easy to use, with all the features you need to run a successful community.
Features:
-Fast and simple.
-Flarum is built with PHP so it’s quick and easy to deploy.
-Flarum is carefully designed to be consistent and intuitive across platforms, out-of-the-box.
Rating:
Flarum’s rating is 4,5 stars out of 5 stars.
2. SMF
SMF is a free, professional grade software package that allows you to set up your own online community within minutes.
Features:
-Comprehensive template system.
-Advanced permission and user management.
-Supports multiple languages at once.
-Open and well-documented source code.
Rating:
SMF's rating is 4,5 stars out of 5 stars.
3. MyBB
MyBB is a free bulletin board system software package developed by the MyBB Group. It it easy to use.
Features:
-Have an unlimited number of members, forums, posts, threads - and anything else.
-As many copies as you like, one database.
-Powerful user control panel.
-Advanced private messaging system with tracking and multiple folders.
-Moderator control panel allowing moderators to perform some light administrative tasks, such as announcement management, moderation queue management for the forums they moderate, and basic user profile editing.
Rating:
MyBB's rating is 4,5 stars out of 5 stars.
Here was my 3 suggestions for forum creation apps.