@husoi mentioned about a TMBF App thats available
Its not an app as such but uses the browser to create a shortcut that can be used like an app providing a direct link to the forum.
I have copied and pasted the information below from the Invision community website so you can "install" it if you so wish
There is also some info on Mobile notifications too
Invision community provides support for push notifications on mobile devices. This will allow you to get notifications on your phone, even when you do not have your browser open, to alert you of new content on followed items and more.
The following will show how to set this up on iOS and Android devices, on their default
iOS / Apple Devices
On apple devices, when visiting the community, you can click on the "Share" icon at the bottom of the page to add this to your home page.
Share icon on iOS
You will see "Add to Home Screen" at the bottom of the list
Adding to the home screen
It will allow the user to change the name of the icon they will add to their home screen should they wish to do so, then will add it to the home screen as a native application, which you can then move around as you can with any other application
Changing the name and adding
Android Devices
On android devices, when visiting the community you will be shown at the bottom of the page (chrome is used in this example) that you can add the application to your home page
Add to home
If you do not see this, you can select the browser menu, where you can then find the option to add the application to your home page
Add to home on menu
Once selected, you will be prompted to add it, which will then show on your desktop. Of course you can move this around as you can with any other application.
Enabling Notifications
Once this is added, if you wish to get push notifications, you will need to switch them on. Click on the item that has just been created to open your community (ensure you do it from the new application icon). Once in there go to the following location
Menu->Bell Icon->Notification Settings
At the bottom of the page, click to enable browser notifications under the "Push" section
Enabling Push Notifications
Notifications in action