On Android there is an official Spinbetter app on Google Play; on iPhone no App Store listing could be confirmed, so you use Safari and add the site to your home screen. Third-party APK files are not needed - see each platform page for what's confirmed.
On Android, install the official Spinbetter app from Google Play (see the Android page); on iPhone, add SpinBetter Casino to your home screen from Safari. Skip third-party APK sites. Either way you keep your existing account and balance.
Apple and Google both restrict real-money gambling apps in most regions, which is why many offshore casinos ship a web app (progressive web app) instead of a store listing - the Google Play listing for SpinBetter Casino is the exception rather than the rule. It's typically not a downgrade - the web app runs the same game library and cashier as the desktop site and updates itself automatically. See the platform pages below for what we could verify for SpinBetter Casino specifically.
On Android, yes: there is an official "Spinbetter" listing on Google Play (package gbcorp.c214.spb.official), which opened from a Canadian store view with 100+ installs when checked. On iOS no App Store listing could be confirmed, so iPhone play stays in Safari. With a real Play listing there is no reason to sideload an APK from a third-party site.
A home-screen shortcut opens the same site, so it uses the same account, cashier and game library - it just adds an icon. See the platform pages for specifics.
