Host Web versus App Web Case Study – Clients

App Web versus Host Web in Office 365 Apps

Chris O’Brien and I have had a running conversation about the merits of using the host web versus the app web as the container for app functionality. If you’d like to catch up on the conversation, it has gone thusly so far:

In Chris’s last post he softened his position a bit. This post is an actual example that compares the client management features in the free trial versions of Instant Practice Manager (the ones in the marketplace) which use app webs to the standard versions which use host webs (which we sell directly because they use a higher level of permissions than the marketplace allows).

Office Integration

On the surface the two versions are hard to tell apart, but in a ghetto web app web there are no rich client integration features like Outlook and document library synchronization and this difference has a profound effect on the user experience.

Clients view in app web


Clients view in host web

When Outlook is available you can connect the list to Outlook and create or edit clients in Outlook as well as perform mail merges.

Not to mention features for individual contacts.

You get similar benefits with the calendar and task features.

Document Synchronization

Document synchronization is another major advantage of a host web compared to an app web. The screen shots below show the Documents tab in the app web version and in the host web version.

App Web

Host Web


A synchronized document library is a huge time saver, especially if you have folder structures you always want to copy or many documents that you need to file.

Working with the client’s documents in Windows Explorer

Synchronized with the client in SharePoint

This synchronization capability is something that can be leveraged in so many cases. It works particularly well when combined with a document scanner like the Fujitsu ScanSnap.

There are many more advantages to using a host web (and upgrading to the standard edition of Instant Practice Manager) that I won’t go into here, but hopefully this will convince Chris that choosing an app web over a host web is not something you should do automatically. The choice will make a big difference to your users!

Technical Notes

There is only one code base. All provisioning is done via CSOM in processes hosted in a Windows Azure worker role. The architecture is fairly complex, but the code itself is relatively simple. The key is that using features in an app package is to be avoided because they only support app web deployments.

I will be announcing public training classes soon and as always, we’d love to hear from you if you need consulting help or would like to license the framework. If you are interested in either please send us an email at

Author: Doug Ware