Graphhopper API vs Graphhopper app

I'm using Graphhopper core library to compute distance and best path between 2 points, i read about Graphhopper Routing API and as explained here, API has a pricing scheme , so my question is what actually will the add-on that's provided by API that's not exist inside APP that worth paying ?

Not sure if this belongs to SO, but here you have a rough guidance.

Advantages of the GraphHopper Routing API:

• hosted and fault tolerant service with support
• highly optimized configuration
• frequent software updates (runs cutting edge & tested versions)
• frequent data updates (usually daily, guaranteed weekly)
• no need to buy servers with >50GB RAM that are usually required to run a world wide setup
• integrates easily with jsprit via optimize=true or the Route Optimization API
• with truck profiles out of the box
• improved heuristics to calculate ETAs with OSM data (we work on making this open source hopefully soon)
• optionally instead OSM data with TomTom data and time dependent historic traffic data
• other APIs like the Matrix API, see the comparison table here and reasoning about closed vs. open source here

Advantages of the open source project (Java knowledge required):

• highly customizable to e.g. tune country or use case specific rules. (this is now also available for the GraphHopper Routing API via a dedicated setup)
• write any vehicle profile
• active community
• import of any data source (can read osm xml, pbf, shp, custom) for the road network or for elevation data
• runs offline e.g. on Android or iOS
• currently public transit routing is only available in the open source project
• find nearest point API (can be simulated with a routing request where start=end)
• can do indoor navigation in theory, in practice have a look here