The Cyanogen Installer app was voluntarily pulled from the Google Play Store earlier in the week. While disappointing to see, it was said the Installer managed to get "hundred of thousands" of downloads in the time it was available. If nothing else, that suggests a decent amount of users are interested in running Cyanogen, but want an easier path to installation.
With that in mind, the good news is the CyanogenMod Installer app is still available for download. Just not by way of the Play Store. Those still looking to use the Installer can grab it direct from the Cyanogen website. And in fact, there isn't much difference going this route as opposed to getting the app direct from the Play Store.
The biggest difference we see is in the "unknown sources" setting. Because the apk isn't being downloaded from the Play Store you will need to sideload it -- which really just means that you will first need to navigate to Settings -> Security and make sure the "Unknown sources" option is checked. From that point, you download the Installer app from the GetCM website and then get the Windows Installer companion app.
Thankfully though, the folks at Cyanogen have provided detailed directions, which is really just a four step process. Bottom line here, aside from not being able to get the app from the Play Store, it remains available and aside from that one extra step -- things haven't really changed all that much in terms of using it. Those looking to get started with Cyanogen should hit the source link sitting below.