If you know me then you know I’ve been doing a lot of work with apps lately (SP2 – link, twitter).  I started developing primarily with an on-premises virtual machine running SharePoint 2013, but I have recently switched to using SharePoint Online (Office 365) more.

1. Free Office 365 Developer Site – The first benefit is that you can sign up for a free Office 365 Developer Site.  This is a great way to get your feet wet with SharePoint 2013 without having to worry about installation and configuration.  You can create a developer site collection and publish your apps here and get started very quickly.  Especially if you use the “Napa” Office 365 Development Tools.
2. Less setup – setting up SharePoint 2013 has a fair amount of complexity, but nothing that most of you can’t handle.  However, setting up apps is even harder as you have to set up a wildcard DNS entry to do it correctly.  Office 365 takes care of all of this for you.  Your subdomains are automatically provisioned for your apps, all you have to do is publish and you’re good to go.  If you plan on using provider hosted or auto-hosted apps, SharePoint Online is easier as well.
3. You don’t have to set up Workflow – Setting up workflow is hard.  I messed it up on my last attempt on my SharePoint 2013 virtual machine and I haven’t bothered to go back and fix it.  When I needed to build an app that used workflow, I started publishing to SharePoint Online.  It just works here and you don’t have to worry about installing Workflow manager and all of the related items.
4. Seller Dashboard team tests here – I discovered this when one of my apps was failed a while back and the issue only occurred on my SharePoint Online tenant.  The nice thing about apps is that once everything is configured they work in both on-premises and in the cloud (depending on the type of course).
5. You don’t need SharePoint 2013 installed – You can develop SharePoint apps without having SharePoint 2013 installed.  This means you can do the development directly from your host OS. 
6. Test Licensing App – If you are doing license validation (and you should), the Test Licensing App helps you test this much easier.  It allows you to generate a test license for free, paid, and trial apps.  I believe this app is self-hosted (or maybe auto-hosted) which means it is much easier to get running with SharePoint Online.  When you do install it, be sure and wait several minutes before trying it because it takes some time before it will work.  If you don’t use this app, you have to create XML files to represent the test license and install them with PowerShell.
7. Testing with latency – some of your users are likely to use SharePoint Online.  When running in the cloud, things have more latency than on-premises as you know.  As a result, some JavaScript that you write may perform greatly on-premises but not so well in the cloud.  This is a great way to test for this and see if you need to make any adjustments or add caching.

I have also found that publishing to SharePoint Online really doesn’t seem to take any more time that it does locally (most of the time).  The biggest drawback here is that you can’t debug workflows.  That may be a deal breaker at some point, but hasn’t been a problem for me yet.  You can debug your JavaScript using Visual Studio just fine though.

Follow me on twitter: @coreyroth.