Mobile - What is the best system for managing Push Notifications between multiple apps?

Appoxee - http://www.appoxee.com has most of the features you described. Disclosure - I was one of the founders - that said, it's still the BEST solution for the needs you just described :)

Based on experience, push notification is a killer feature: an app with push notifications engages your user in a unique way and people ask for it.  Look at our apps in http://limitedescurities.com, we guarantee you that we will be selling none if they did not have push notifications as a core feature.  The point I am trying to make: take push notifications serious and do not be fooled with comments like 'you can push from your own iPhone'.   Now, based on experience as well, you will always need some sort of server, even if it is a "broadcast" type of push, where all users receive the same message, if you want to do this somehow automatic; you will need a server at the very minimum to connect with Urban Airship (free service) servers.   But if you are seriously serious about push notifications, you will be sending customized pushes to the owners of your apps, like in these sample images: http://limitedsecurities.com/icurrency-iphone-notifications.html ... Do you see that the message was customized for that particular user?  For this you will need to host web services, DBs and some sort of calculation engines that decides what to push to whom and when.   If you have the previous, doing what you just mentioned is nothing.  Contact us if you need more details, perhaps we can reach some agreement and we can co-host your engine :-)

Check out https://commandiq.com/ – It empowers your marketing team to send, test and optimize individually tailored calls to action coordinated across all of your apps and communication channels.   CommandIQ tracks the behavior of every person who receives push or email from you – across all of your apps using any unique identifier- making the raw event data accessible through the http://blog.commandiq.com/2014/07/now-that-we-send-more-email-our-users-are-more-engaged-but-are-they-spending-less-now-youll-actually-know/). It calculates performance “bottom up” from the actions of your message recipients, allowing you to track conversion between apps using your own customizable definitions (e.g., downloaded app, opened app greater three or more times in first three days, etc.)   Happy to chat more about your use case if you’re still looking for a solution.

http://www.PushBots.com supports geo-targeting and segmentation and for free!

I would be happy to elaborate on Lior's answer above. feel free to contact me