# Objective
`SubApps` is visible within the documentation for `bevy_app`. However,
no way of accessing the `SubApps` field in `App` is currently available.
## Solution
Expose two new functions, `App::sub_apps()` and `App::sub_apps_mut()`,
which give immutable and mutable access to `SubApps` respectively.
The other solution is to hide `SubApps`, which I submitted as a PR at
<https://github.com/bevyengine/bevy/pull/16953>.
## Testing
Because of the simplicity of the changes, I only tested by compiling
`bevy_app` - which compiled successfully.
Note: `SubApps`, and its corresponding field on `App`, are not used
outside of `bevy_app` - which means that compiling the other crates is
not necessary.