Apps aren't being compiled here. Apps already exist and new platforms and platform functionalities are being made available.
Launching platforms is an eternal chicken and egg problem: You want to launch a new platform. Users want apps before they buy into the platform. Developers want users and a guarantee they will spend money before investing time and money building apps for the platform. If you're really really rich, you can literally pay developers to write apps for you, but ask Microsoft how that went with Windows Phone.
Instead, the most reliable way (I said most reliable, not reliable) is to leverage an existing group of apps onto your platform. Maybe you have a phone ecosystem and want to get into tablets. So you take the already existing phone apps in your store and let them run on your new platform.
There is no recompiling. There is no build.
There is no "build" because the source code was lost when all of the company's assets were sold off in 2002.
There is no "build" because the developer made a game, put it on your app store, moved on to the next game and has no interest in supporting this game that isn't providing any significant new revenue.
There is no "build" because this is FooManager 6.0, the company that makes FooManger wants everyone to buy FooManager 7.0 and isn't making any further changes to 6.0.
etc. etc. etc.
Binary compatibility is what matters. Nothing else is of particular significance.
In addition, if recompiling an app for your new platform yields compile errors and requires work (as opposed to targeting a new platform version in a manifest and just hitting build), developers on your platform are significantly less likely to spend the time to do so.
Launching platforms is an eternal chicken and egg problem: You want to launch a new platform. Users want apps before they buy into the platform. Developers want users and a guarantee they will spend money before investing time and money building apps for the platform. If you're really really rich, you can literally pay developers to write apps for you, but ask Microsoft how that went with Windows Phone.
Instead, the most reliable way (I said most reliable, not reliable) is to leverage an existing group of apps onto your platform. Maybe you have a phone ecosystem and want to get into tablets. So you take the already existing phone apps in your store and let them run on your new platform.
There is no recompiling. There is no build.
There is no "build" because the source code was lost when all of the company's assets were sold off in 2002.
There is no "build" because the developer made a game, put it on your app store, moved on to the next game and has no interest in supporting this game that isn't providing any significant new revenue.
There is no "build" because this is FooManager 6.0, the company that makes FooManger wants everyone to buy FooManager 7.0 and isn't making any further changes to 6.0.
etc. etc. etc.
Binary compatibility is what matters. Nothing else is of particular significance.
In addition, if recompiling an app for your new platform yields compile errors and requires work (as opposed to targeting a new platform version in a manifest and just hitting build), developers on your platform are significantly less likely to spend the time to do so.