They offer a combination of both internal and external app optimization services. Relatively expensive, considering that most of the services you pay for are impossible to track (meaning you just take their word for grated).
Their services are oriented towards internal ASO. I think it's a worthy service if you're looking to outsource an important part of your app's launch (designing icons & screenshots, description writing, keyword research).
The only service I found that focuses on external ASO (app reviews on app review websites, app submission, press release submission, pr management, app installs). Their bundles are quite nice.
Another internal focused ASO service. Can't figure out what some of their package features mean (powerful social signals?)
You are welcome to contribute to the list!
Regards, Daniel C.