My app won't open anymore was it iOS 8 Thats making this happen?

Space Relapse il y a 6 ans mis à jour par Josh Hayman il y a 6 ans 3
When I click it it loads for 1 second then shuts down i tried resetting my phone several times and closing the app and it still won't work 
You need to reinstal the app. However, now there is a problem where it no longer gives you the option to download the video you are watching.
will my already downloaded videos get deleted after reinstalling the app?