Developer Console

App Design and Modification Requirements and Guidelines for Amazon Underground


If you have either submitted an app to Amazon Underground or are considering submitting an app, you might be wondering if you need to make any design changes to your app for Amazon Underground. To help you best prepare your app for Amazon Underground enrollment, this document provides guidelines and suggestions for maintaining or enhancing the user experience (UX) and enabling other benefits for you and your customers. In general, Amazon supports the following types modifications for Amazon Underground:

  • Enhancing the user experience, such as providing exclusive character outfits or tools for Amazon Underground users. You cannot remove anything from the Amazon Underground version of your app. Make sure to call out anything new that you add for Amazon Underground users in the description fields of your app's submission package.

  • Adding other positive benefits for the user.

You may not make changes to your app simply to increase user engagement time and royalty payments without adding value for your users. Modifications such as extended cut-scenes, interstitials, cinematics or other sequences that are passively viewed by a user are not permitted.

Keep in mind that any changes that you make to your app must ensure that the Amazon Underground version of your app is substantially similar to or better than the non-Underground version, as stated in the Amazon Underground eligibility requirements:

[Amazon Underground Eligibility and Submission Checklists][underground/amazon-underground-eligibility-and-submission-checklists]

Maintaining the Look-and-Feel of your App for Amazon Underground Users

The Amazon Underground version of your app should retain the look and feel of the non-Underground version. The following sections call out some specific examples of features and experiences to make sure that you appropriately port your app from the non-Underground to the Amazon Underground version of your app.

Branding and Identity

The Amazon Underground version of your app must retain the same branding, identity, and gameplay elements as the non-Underground version of your app.

Users should be able to easily recognize the Amazon Underground version of your app as the title that they are already familiar with. They should not feel like they are playing a limited edition or trial version of your app. You must port your overall app branding from the non-Underground version of your app to the Amazon Underground version.

In addition to the required branding migration, Amazon recommends porting the non-Underground version of the following features over to the Amazon Underground version of your app:

  • Game or app controls
  • Unlockable items, such as levels that are unlocked as the game progresses
  • In-app consumable and entitlement items, such as "magic hammers"
  • Awards and badges
  • Leaderboards and other aspects of the app's user community

In-App Advertising

The following guidelines related to in-app advertising apply to the Amazon Underground version of your app:

  • If the non-Underground version of your app did not previously contain advertising, do not add advertising to the Amazon Underground version of your app.
  • If the non-Underground version of your app contains in-app advertising, you may keep the same amount or decrease the amount of in-app advertising for the Amazon Underground version of your app. This guideline applies to both the number of advertisements run in your app and the duration of those advertisements.
  • If the non-Underground version of your app contained ads and offered an IAP item to remove the ads, remove both the ads and the appropriate IAP item from the Amazon Underground version.
  • You must not require a user to watch advertisements to unlock IAP items or other rewards.

As a general rule, you may not increase the amount of advertising within your app for Amazon Underground.

Keeping Your Icons Looking Sharp on Fire OS 5

For increased commonality with Android, the launcher on Fire OS 5 displays the app icon that you provide within your APK. This is a change from earlier versions of Fire OS, where the launcher used the app icon that you uploaded to the developer portal when submitting your app. See the Launcher Icon Guidelines for information about required icon resolution and dimensions.

Test your icon across the range of devices where you want your app to run, and make sure that the icon provides a clear and identifiable image that your customers recognize that positively represents your brand.

When you create an icon for Amazon Underground, use the "Actually Free" sash overlay that corresponds to the pixel dimensions of your icon. You can find sash overlay images at See [Migrating Your App to Amazon Underground][underground/migrating-your-app-to-amazon-underground] for more information about the sash overlay.

Increasing the Perceived Value of Your Amazon Underground App

Ideally, users of your app should perceive the value of the Amazon Underground version of your app to be greater than that of the non-Underground version. Increasing the perceived value of the app can help increase customer loyalty and engagement, thereby potentially increasing the royalties that you receive from the Amazon Underground program. Consider implementing the following features to help increase customers' perceived value of the Amazon Underground version of your app, and to therefore increase their app usage:

  • Remove in-game advertising: If the non-Underground version of your app contains in-app advertising, consider removing that advertising from the Amazon Underground version of your app. Removal of advertising is a fairly standard "premium" feature, such as when users can opt for a premium, ad-free version of an app for a few dollars versus a free version of the app with ads. In fact, removing ads from an app that previously contained ads is one of the most visibly apparent changes that enhances value for the app's customers.

  • Add Amazon Underground-exclusive items and rewards: If the non-Underground version of your app includes personalization items, such as characters or clothing items, consider adding some additional items that are exclusive to the Amazon Underground version, and make these items available for free to the customer immediately. If you add exclusive items, make sure that you call these out in the descriptions for your app submission package. For example, "in this version you get a special blue dress valued at $.99 for free.”

  • Display strikethrough pricing within your game: If your app maintains a store, whether driven by IAP or an “entitlement selector” created in your app code, consider showing strikethrough pricing, based on the price of the item in the non-Underground version. For example, if the “Magic Hammer” costs 99¢ in the standard version, update your app's Magic Hammer icon to show strikethrough pricing. The updated icon would show “99¢” crossed out and “Free” next to the price. Strikethrough images help communicate the value that customers are receiving in the Amazon Underground version of your app.

  • Update your app's descriptions: Describe the additional value provided by the Amazon Underground version of your app in the app's long and short descriptions in your submission package.

Adapting In-App Purchasing (IAP) for Amazon Underground

Any In-App Purchasing (IAP) items in the Amazon Underground version of your app must always be free to Amazon Underground users. If your app incorporates IAP, the Amazon Underground program has the following minimum requirements for adapting existing IAP items for Amazon Underground:

  1. When creating the new app submission for Amazon Underground, re-create all of your IAP items with new SKUs and set those items to their original prices.

  2. Update your app's code to reference the new, Amazon Underground versions of the IAP SKUs.

Amazon applies strikethrough pricing to these items in the Amazon Appstore, showing users both the old cost and that these items are now free. (These strikethrough visual cues are different from the icons within your app.)

If the non-Underground version of your app features IAP items that are particularly popular, ensure that these items continue to be available in the Amazon Underground version of your app. Amazon Underground app users should never look for a popular item only to find that item missing.

While recreating your IAP items as part of your app submission fulfills the minimum requirements for Amazon Underground, remember to keep your IAP items intact and allow Amazon to mark the prices down to free. Amazon's strikethrough of your prices helps your customers understand the value being provided.

Use the following guidelines to adapt your IAP implementation to Amazon Underground:

  • Remove or hide IAP items that have no usefulness in Amazon Underground, such as an in-game currency that can be purchased via IAP and is only used to buy other IAP items. You will need to keep all other IAP items (and their list prices) for Amazon Underground, and Amazon will mark them to free.

  • If you remove an in-game currency, such as "coins" that previously could only be purchased through IAP and would be used to buy IAP items, keep the prices of the remaining IAP items, so that they can be marked as free. Amazon Underground users should not encounter a situation where previously purchased IAP items are no longer accessible to them.

Social Sharing

Amazon encourages you to find creative ways to utilize social networks, such as Twitter or Facebook, to share the Amazon Underground version of your app with others. Promoting your app on a social network helps you find new users and boost engagement. However, avoid tying social sharing to advancement within an app or to unlocking an IAP item.

Keeping Gameplay Fair and Balanced Across Amazon Underground and non-Underground Versions

If the non-Underground version of your game includes leaderboards, the Amazon Underground version of your game should share those same leaderboards. Amazon Underground players should not be segregated to separate "Amazon Underground version" leaderboards. These players should be able to play and interact with users of the non-Underground version of your game in the same ways as non-Underground users. However, to keep play fair and balanced across gameplay versions, consider the following aspects of gameplay:

  • Keep game balance, expected progression rates, and potential for player success fair across Amazon Underground and non-Underground platforms. Do not force Amazon Underground players to wait a certain period of time to unlock new levels.

  • Cross-platform multiplayer economies present special challenges in Amazon Underground, and successfully implementing such economies so as not to disrupt the overall game world requires particular care. At first glance, you might be tempted to segregate Amazon Underground players from non-Underground players as the easiest way to keep things fair. However, this easy solution does not necessarily provide the most engaging experience for your customer base.

Migrating Player State and Progress

Players who move from the non-Underground version of your game to the Amazon Underground version expect to retain their levels of progress. If players of the non-Underground version have hit level 20, move to the Amazon Underground version and are unceremoniously restarted at level 1, they are likely to be frustrated and unhappy. Unhappy customers may abandon your title entirely, return to the lesser monetizing non-Underground version, or contact your app's customer support with costly complaints.

Use the following guidelines to best determine which aspects of player progress you should migrate from the non-Underground to the Amazon Underground version of your app:

  • Wherever possible, migrate meaningful game state and player progress from the non-Underground versions of the app, including iOS versions, to the Amazon Underground version:

    • Previously earned or paid for in-app currency.
    • Leveling Amazon Underground players up to a comparable state.
    • Unlocking lower levels and items.
    • Entitling Amazon Underground players to inventory items that they previously collected, such as "magic hammers".
    • Migrating high score records.
  • Some aspects of game state might be impractical or inappropriate to migrate. Find an appropriate way to address these technical limitations for Amazon Underground players.

  • If for some reason, you cannot migrate your players' progress, mitigate this issue by appropriately setting your customers' expectations. For example, if the app is a multi-player Role Playing Game (RPG), and you are implementing an exclusive community for Amazon Underground users that requires them to start over, communicate this decision to the user in a sensitive, but direct way.

See [Migrating Users' Progress][underground/migrating-users-progress-between-app-versions] for instructions on migrating user app state and progress.

Last updated: Jul 13, 2017