can't update to latest version iOS

From AppStore update page it gets to what looks like 100% (full circle) but then never changes to open. Left it for ages and nothing happened. Tried 3 more times and same issue.

Uninstalled the app, restarted device and tried to download the game again, same problem from the purchased apps page, hangs on what looks like 100% with no option to open the app.

Using iPad Air and latest version of iOS on a face broadband connection.

Please help, I forgot to write down my user ID before I uninstalled too :-(