Create a Mobile App

I have a request for an App development

Based on the app „Latest Sightings“ which is available for Kruger Nationalpark in Southafrica I would like to have a similar app which can be made accessible globally.

Per animal sighting I would like to have the following information:
-Date and time
-Visibility
-Photo (optional)
-The sightings should be placed via Google Maps which could serve for other useser to navigate to the location

Further functionalities:
-library of information for each animal
-„following“ other users and building user groups
-being able to filter out historic seightings
-set alerts for specific animals

Can you indiacte very rough pricing for such an App for IOS and Android?

Thanks