It's still early work in progress and I've only tested with a few apps so far. Also test coverage could certainly be better. If you find any issues, feel free to ping me up (@vpdn).
The Podspec seems a little screwy, it's not installing the actually library files, just the PSDWriter classes.
Edit: I notice the pod spec has changed since the tag - maybe you need to tag a new 0.1.1 ?
Edit 2: Using "pod 'MMLayershots' :head" in the pod spec still doesn't work.
Update: There's a transitioning period currently ongoing at Cocoapods (migration to Cocoapods Trunk). For now please use the updated podspec in the github repo directly:
pod 'MMLayershots', :podspec => 'https://raw.githubusercontent.com/vpdn/MMLayershots/master/M...
pod 'MMLayershots', :git => 'https://github.com/vpdn/MMLayershots.git'