Develop Reference

Cross-Marketplace In-App Billing

Has anyone come across any design patterns / suggestions / libraries to cleanly implement a way of introducing in-app billing in an app across multiple marketplaces such as Google Play, Amazon App Marketplace (which now has In-App purchasing as well) ?

This may be a good source for a starting point but states it is not production ready.
RoboBilling on GitHub

Here is another one that looks on subject - SOOMLA on Github
I noticed there is also a sample app

Good in-app purchase SDK for non-Google Play markets

Our game relies on in-app purchases. Currently they use the Google's own system for that. But we get many requests from smaller app markets around the world to put our game there. But not having in-app purchases would seriously cripple the game mechanics.
But from what I've searched, there doesn't seem to be good alternatives. Amazon has it's own, but it's in invite only beta phase. Samsung apparently has it's own.. I would love to find a simple micropayment SDK to use in all these smaller app markets.
Any ideas?

PayPal should work, although you will need to do some work to implement managed items on your own server. Some of the major 'smaller' markets have their own API on top of PayPal.
BTW, Amazon's in-app purchase library has been publicly available for a while: http://www.amazonappstoredev.com/2012/04/announcing-the-in-app-purchasing-api-for-kindle-fire-and-other-android-devices.html

How to Implement Microtransactions on the Amazon Appstore?

My company has an app that is available both in the Google Market and the Amazon Appstore. We're now looking to implement DLC in-app purchases. This is no problem with Google but it looks like Google doesn't allow 3rd party app stores to use their in-app billing system.
Since we were free the first day on Amazon and have considerable users who downloaded our app freely we're trying to implement pay-DLC on Amazon to recoup the lost revenue. Google aside, I'm sure there are other ways to handle in-app purchases, any suggestions that people have had experience with that involve simple, streamlined, & secure APIs for this?

Amazon Appstore for Android does not yet support In-App Purchasing (aka In-App Billing). However, there is a beta of an SDK they are developing, and access to that SDK is by invitation only (again, as of this writing). You can sign up here:
http://www.amazon.com/gp/html-forms-controller/AmazonAppstore-IAPrequest

I am not aware of being able to use in-app purchases to buy from the Amazon Appstore. (I would post this as a comment but I can't seem to find the comment button.)
The only thing I can think of would be to update your application to look for files outside of your app - specifically additional content. An example would be PowerAmp, where it can use an unlocker to keep going, but it would be more useful... However, I don't think the app-store lets you do that.
You might just have to stick to the market.

Amazon's In-App Purchasing API (IAP) is publicly available. You can download the Amazon In-App Purchasing API, Documentation, sample code, and testing tools here:
https://developer.amazon.com/sdk.html
*Opinion's expressed are my own, not my employer's. For official Amazon Appstore policies and guidelines, please refer to http://developer.amazon.com

Donate via in-app billing

Is it possible to donate money via in-app billing?
If not, how can we implement donation from inside an Android app? Please share a few hints.
Thanks

There isn't really a mechanism for doing donations in in-app billing. Anything you sell needs to be sold as virtual goods - fixed products with fixed prices. It is possible to sell "unmanaged" items which a user could buy over and over again but it'd be really in-convenient for your users.
What you might want to look into is the PayPal in app payments library.
https://www.x.com/community/ppx/xspaces/mobile/mep?view=overview
If you're not selling virtual goods I think it'll give you more flexibility - for instance your users can input the amount they're willing to donate + you can do recurring payments with it ;). Also, it's MUCH easier to integrate with your app than the in-app payments system.

If you are using in-app billing then market will charge 30% for a transaction. While in-app billing requires items to be sold on a fixed price which will give you a little scope if your items are not managed(fixed priced). There is a way to do it from your android app without leaving it by using Paypal libraries.
Paypal integration for android becomes fairly simple if you follow their developer site. You will need to download and integrate the library provided by Paypal, which is available on Paypal developer site.
Sample Pizza application built using Eclipse demonstrate how to do actual integration which is quite simple. Although paypal seems forgot to use relative path for library. So you will have to change library path and application is ready to go.

Implementing In App purchases in Android?

Edit: Android now supports in-app billing!
Original question:
It looks like Android won't natively support in-app purchases for a while, and when it does there might be a huge user base with devices that don't support them.
What's the best way to implement iPhone-like (additional content or services) in-app purchases in Android using the Android Market if possible?
The solution should consider in particular:
For all kinds of in-app purchases: Android Market's 24-hour cancellation policy
For consumables/non-consumables: storage of additional content (ie: use precious application memory to avoid piracy, or use SD card to avoid bloating application memory)
Thanks!

This has changed as of today! There is now an example on the Android Developer site here: https://developer.android.com/google/play/billing/billing_overview

You can create a premium key application, that will have a key. How you expose that it's your deal ( or you can just check if PremiumKey activity exist ). From the main app you just check for your key and if it's exist enable premium option )
If you're talking about buying OTHER apps from yours - build your list with market url pointed to the other apps ( market:// )

It is against the Android Market Developer Distribution Agreement to take in-app payment:
3.3 ... All fees received by Developers for Products distributed via the Market must be processed by the Market’s Payment Processor.

Looks like Paypal has launched a library for accepting in-app payments. See here. Not sure if this system violates the T&C though.

You say that Android Market doesn't support in-app purchases, and then ask how you can implement in-app purchases using Android Market?(!)
Anyway, if and when they do support it, I imagine it could be distributed as an update to the Android Market application itself, so most users would be able to use the functionality. I believe the Market app updates itself automatically.
Possibly the Market would accept an Intent to trigger a payment via the usual on-device mechanism and return your app (or more likely your server) a callback.

There is also another in-app payment platform for Android applications called MoVend (www.movend.com). I have checked it out and there are several benefits using it compared to the other 2 mentioned earlier:
Many payment channels : Operator Billing for more than 38 countries, PayPal and virtual credits.
Many distribution channels: They work with developers to distribute their applications through the various distribution channels like Operator AppStores , OEMs and Android applications website. Marketing is something we all need. They are also invested by Singapore Telecommunications who has a strong presence in South East Asia.
They provide a sales analytics for you to track, trace and monitor the performance of your apps. Since they are available worldwide, you can always tailor your applications to the different geography area.
I am trying to build Android applications and monetizing is important.
Reply this thread so we can discuss how we can monetize our Android applications.

Here's another free licensing and payments system. The nice thing about this one is that it allows you to offer your app in any app store.
You can find more details # http://www.cloud4apps.com/

Check out http://mobpaynet.com, they are doing something like this. Not sure if it violates terms or not, but I will probably check it out.

For implementing in-app purchases in Air applications you may use third-party libs (Adobe AIR does not support In App Purchases for any platforms out of the box). For example, developed by Milkman Games (unfortunately, they are not free)