Q: Unable to install Google Maps

What is the error?? When trying to install does it give you any information??

Have you checked you have enough free space on the phone from Settings > General > Storage??

Are you sure the app was deleted?  Perhaps it got moved (into a folder or another screen)?  Try searching for it:

Use Search on your iPhone, iPad, or iPod touch - Apple Support

Sounds simple, but have you tried Restarting the phone?? I have had a situation where I have a app Waiting constantly, rebooted the phone and it went away. Might of got stuck downloading somewhere and got itself confused

I tried restarting too.... but nothing works