Looking for an iOS app for my poi

You really need to give more info to get answer. Phones van use different mapping software, and not every navigation program allows for custom POIs.

But id doesn't hurt to look into forum first. Like here:
http://www.poi-factory.com/node/42168

or look on internet:

http://help.sygic.com/hc/en-us/articles/540095-Import-of-ext...

You may need a custom app. I have created various iPhone apps from POI Factory data (with the author's permission). For example, there's Offbeat Tourist Attractions available at
https://itunes.apple.com/us/app/offbeat-tourist-attractions/...
It's free, and uses the data compiled by Bob from the POI Factory.

But I don't think there's an off-the-shelf app that does what you want.

Well, there is POIViewer.

https://itunes.apple.com/us/app/poiviewer-manage-your-pois/i...

You can load POI files via iTunes or via Dropbox, iCloud Drive, etc.
You can get alert for all the POIs or a selection.
It can open directions to a POI in a lot of GPS apps (Google Maps, Apple Maps, Tomtom, etc)

Disclosure: I am the developer of the app.