Once an auction or marketplace site is running, the next question is usually "can we have an app?". Customers who install an app come back more often, and push notifications reach them when something happens: they're outbid, they win, their order ships. This guide covers the Mobile App add-on for BidKing and PrizeX. It explains what you get, which events send a push, what you still do yourself in the app stores, and the store policies to check before you submit.
What the add-on gives you
The Mobile App add-on is available from Add-ons in your admin panel. It turns your store into an Android and iPhone app under your own name and icon.
- The app's full source code, not a ready-built app. You download it from the App & push page in your admin. It comes already set up with your site's address, your store name, your app ID, a background colour to match your theme and, if it's a PNG, your logo. A step-by-step guide comes with it.
- An app that shows your live site. It's built with Capacitor, and it opens your real store rather than a copy. Anything you change on the site, from a new listing to a new theme setting, shows in the app straight away, with no new app release.
- Push notifications through Google's Firebase Cloud Messaging, which is free to use.
- Native touches:
- an offline screen in the phone's language;
- links to your site that open in the app, once you add your signing details;
- Google and Apple sign-in inside the app, with the matching login add-ons;
- other websites opening in an in-app browser.
Before you build, a Before you build checklist on the same page flags common problems:
- a site address that isn't https;
- the example app ID left in place;
- a store name too long to show under the icon;
- a logo that isn't a PNG;
- Firebase files that don't match your app ID.
Which events send a push
Once you upload your Firebase service-account file on the App & push page, the app asks customers for permission and registers their device. These events then send a push, each in the customer's own language:
- Outbid on an auction. To avoid flooding, it's sent at most once per auction every 10 minutes, and never for sealed-bid auctions.
- Auction won.
- Lottery prize won.
- Order shipped and order delivered.
- Refund issued.
- Support replied to a ticket.
- Membership payment failed.
A few more things about pushes:
- Each event can be switched off on the What sends a push tab. All of them are on to start with.
- Tapping a notification opens the page it's about.
- The Send tab lets you send a test to one customer, or a message to every signed-in customer who has the app.
- A 90-day history shows each push and what Firebase answered for each device.
- Without Firebase, the app still works. It just doesn't get notifications.
What you still do yourself
The add-on gives you a ready-to-build project, not a listing in the stores. You need:
- Your site online at an https address.
- Developer accounts: a Google Play developer account for Android, and an Apple Developer account for iPhone. Both are in your name, so the apps are yours.
- Tools: Node.js 20 or newer and Android Studio for Android. For iPhone you need a Mac with Xcode.
- Images: a 1024×1024 app icon with no transparency, and a 2732×2732 splash image.
- A Firebase project for notifications. Its config files go into the app, and its service-account file goes on the App & push page. For iPhone notifications, you also add an APNs key in Firebase.
- The build itself: a few commands set the project up, then you build and sign in Android Studio and Xcode and upload to each store.
- Your Android signing key, kept safe. Every future update must be signed with the same key.
- Your app ID, chosen once. It can't be changed after the app is in a store.
Because the app shows your live site, you rarely need a new store release. You need one mainly when the app's own settings change, such as its name, icon or app ID.
App-store policy: check before you submit
Apple and Google review apps like this one closely. The add-on is built to keep a first submission safe, but approval is up to the stores, and nothing here guarantees it.
- Real-money sections are hidden in the app by default. Live auction bidding, lotteries, mystery boxes, investing and chance games stay closed in the app until you switch them on with the Mobile App Settings add-on. Your website isn't affected. Both stores can treat these sections as gambling or financial services, which need licences and country limits. Only switch one on once you've confirmed it's allowed where your app is offered. The operator is responsible for compliance, so check with a local lawyer.
- That includes auction bidding. Until you switch it on, bidding isn't available in the app, and customers who try to bid are told the section isn't available there. They can still bid on your website. Decide this before you submit, and describe it accurately in your review notes.
- Digital items on iPhone. Apple requires its own in-app purchase system for digital items such as coins, wallet top-ups, memberships and tickets. The add-on doesn't use Apple's system. Instead, the iPhone app refuses those purchases by default. Physical products still use your normal payment gateways. Google Play has a similar rule for digital items, so check its Payments policy for your countries.
- Sign in with Apple. If you offer Google sign-in, Apple asks you to offer Sign in with Apple too. Set up the Apple Login add-on before you submit. Facebook login is left out of the app.
- Account deletion. Both stores require customers to be able to delete their account inside the app. It's under Profile › Edit profile › Delete account, and push tokens are removed with the account.
- Privacy. Both stores ask for your privacy policy's address and what data the app collects.
- Age. BidKing limits sign-up to 18 and over, and your store listing's age rating should match.
Common questions
Do I get a ready-made app?
No. You get the app's full source, already set up for your store, and a step-by-step guide. You build it in Android Studio and Xcode and publish it under your own developer accounts.
Will changes to my site show in the app?
Yes. The app shows your live site, so listings, prices, pages and theme changes appear straight away, without a new app release.
Can customers bid in the app?
Only if you switch live auction bidding on in Mobile App Settings. It's off by default because app stores can treat real-money bidding as gambling. Until then, customers bid on the website.
Which push notifications are sent?
Outbid, auction won, lottery prize won, order shipped, order delivered, refund issued, support replied and membership payment failed. You can switch each one off, and you can also message every customer with the app.