Rainbet app: there is not one
Rainbet publishes no mobile application and no official APK. The site runs in a phone browser, and that is the entire mobile offering.
The answer
No app store carries an official Rainbet app, and there is no official APK anywhere. Everything runs in a browser, on a phone as much as on a desktop.
What the apps using the name are
Products do appear under the Rainbet name in app stores and on download sites. They are not published by Rainbet. This site does not link to them or explain how to install one — an unofficial build that asks for casino credentials is the most direct route to losing an account.
Using the site on a phone
The browser version is the complete site. Adding it to the home screen from the browser menu produces an app-like icon that is simply a bookmark to the official address, with nothing installed and no permissions granted.
Related
Checking you are on the genuine site is covered on Rainbet login.
Frequently asked questions
Is there a Rainbet app?
No. There is no mobile app and no official APK.
Is there an APK download?
No official one. Files offered under that name are not published by Rainbet.
Can I use Rainbet on a phone?
Yes, through a mobile browser. Adding it to the home screen creates a bookmark, not an installation.
Browser only
Nothing official to install.