LimaFoxTango
I have by no means a real overview. However, depending on apps the airline uses they might include document distribution. For example the Airbus app suite includes the whole document set for each airplane in the operators fleet in the database and all airbus documentation. However, to customize it is rather costly.
LIDO, if one uses their charting service, can include the whole route manual part of the documents, freeing the company from keeping that updated by themselves, i bet competing companies offer something similar. And then of course companies usually want to use a general document distribution system that is independent of third party companies. I have used in the past inhouse delivered systems that actually worked very well indeed, only available on the private company app store (Apple does allow other than its own app store for commercial users), and for a short while Docunet from, i belive Vistair, which worked OKish but required the user to manually update the documents instead of automatic push-updating. There are likely a lot of different solutions out there, and it can make sense, if you have a competent IT department, do create your own solution catering for any special needs each company has.