Zapier now lists over 1,400 apps that you can connect to. That's a huge number and one that's been climbing rapidly over the last year or two. The reason for this is that Zapier has a DIY developer platform for apps that want to add themselves to this mix.
Without getting into too much detail about the process, apps connect their API via some great tools that Zapier have created. Once built, there is a process that apps must go through to get their integration first working on Zapier, then published in app directory.
One built apps enter a sort of 'beta' mode where they get a invite-only link they can share with customer whom they want to use their integration. It's a good way for apps to test and improve their integration before it gets added to the directory.
Getting included in the directory, however, can be a long process and some apps choose to just stay in invite-only mode and share the link via their website - if you look, you'll probably find an apps invite link on their blog or help docs.
To make life a bit easer for everyone, we've created a directory where you can see all the apps available and quickly get their invite link.
Check it out here.