diff --git a/book/en/src/by-example.md b/book/en/src/by-example.md
index d4527223e4..38985da140 100644
--- a/book/en/src/by-example.md
+++ b/book/en/src/by-example.md
@@ -9,7 +9,7 @@ is required to follow along.
 
 [repository]: https://github.com/rtic-rs/cortex-m-rtic
 
-To run the examples on your laptop / PC you'll need the `qemu-system-arm`
+To run the examples on your computer you'll need the `qemu-system-arm`
 program. Check [the embedded Rust book] for instructions on how to set up an
 embedded development environment that includes QEMU.
 
diff --git a/book/en/src/by-example/resources.md b/book/en/src/by-example/resources.md
index b9e92d1e29..d63d135c83 100644
--- a/book/en/src/by-example/resources.md
+++ b/book/en/src/by-example/resources.md
@@ -4,11 +4,11 @@ The framework provides an abstraction to share data between any of the contexts
 we saw in the previous section (task handlers, `init` and `idle`): resources.
 
 Resources are data visible only to functions declared within the `#[app]`
-pseudo-module. The framework gives the user complete control over which context
+module. The framework gives the user complete control over which context
 can access which resource.
 
 All resources are declared as a single `struct` within the `#[app]`
-pseudo-module. Each field in the structure corresponds to a different resource.
+module. Each field in the structure corresponds to a different resource.
 Resources can optionally be given an initial value using the `#[init]`
 attribute. Resources that are not given an initial value are referred to as
 *late* resources and are covered in more detail in a follow-up section in this
diff --git a/book/en/src/by-example/tasks.md b/book/en/src/by-example/tasks.md
index d0b5acb916..9fefd02273 100644
--- a/book/en/src/by-example/tasks.md
+++ b/book/en/src/by-example/tasks.md
@@ -92,7 +92,7 @@ following snippet:
 
 ``` rust
 #[rtic::app(..)]
-const APP: () = {
+mod app {
     #[init(spawn = [foo, bar])]
     fn init(cx: init::Context) {
         cx.spawn.foo().unwrap();
@@ -113,5 +113,5 @@ const APP: () = {
     fn bar(cx: bar::Context, payload: i32) {
         // ..
     }
-};
+}
 ```
diff --git a/book/en/src/by-example/tips.md b/book/en/src/by-example/tips.md
index b191b9dab4..0b6555e168 100644
--- a/book/en/src/by-example/tips.md
+++ b/book/en/src/by-example/tips.md
@@ -139,7 +139,7 @@ $ tail target/rtic-expansion.rs
 
 ``` rust
 #[doc = r" Implementation details"]
-const APP: () = {
+mod app {
     #[doc = r" Always include the device crate which contains the vector table"]
     use lm3s6965 as _;
     #[no_mangle]
@@ -152,7 +152,7 @@ const APP: () = {
             rtic::export::wfi()
         }
     }
-};
+}
 ```
 
 Or, you can use the [`cargo-expand`] sub-command. This sub-command will expand
diff --git a/book/en/src/by-example/types-send-sync.md b/book/en/src/by-example/types-send-sync.md
index 41cd9ba92c..9cdb88945f 100644
--- a/book/en/src/by-example/types-send-sync.md
+++ b/book/en/src/by-example/types-send-sync.md
@@ -1,6 +1,6 @@
 # Types, Send and Sync
 
-Every function within the `APP` pseudo-module has a `Context` structure as its
+Every function within the `app` module has a `Context` structure as its
 first parameter. All the fields of these structures have predictable,
 non-anonymous types so you can write plain functions that take them as arguments.
 
diff --git a/book/en/src/internals/access.md b/book/en/src/internals/access.md
index 6433707ea1..3894470c09 100644
--- a/book/en/src/internals/access.md
+++ b/book/en/src/internals/access.md
@@ -15,7 +15,7 @@ To achieve the fine-grained access control where tasks can only access the
 static variables (resources) that they have specified in their RTIC attribute
 the RTIC framework performs a source code level transformation. This
 transformation consists of placing the resources (static variables) specified by
-the user *inside* a `const` item and the user code *outside* the `const` item.
+the user *inside* a module and the user code *outside* the module.
 This makes it impossible for the user code to refer to these static variables.
 
 Access to the resources is then given to each task using a `Resources` struct
@@ -29,7 +29,7 @@ happens behind the scenes:
 
 ``` rust
 #[rtic::app(device = ..)]
-const APP: () = {
+mod app {
     static mut X: u64: 0;
     static mut Y: bool: 0;
 
@@ -49,7 +49,7 @@ const APP: () = {
     }
 
     // ..
-};
+}
 ```
 
 The framework produces codes like this:
@@ -103,8 +103,8 @@ pub mod bar {
 }
 
 /// Implementation details
-const APP: () = {
-    // everything inside this `const` item is hidden from user code
+mod app {
+    // everything inside this module is hidden from user code
 
     static mut X: u64 = 0;
     static mut Y: bool = 0;
@@ -154,5 +154,5 @@ const APP: () = {
             // ..
         });
     }
-};
+}
 ```
diff --git a/book/en/src/internals/ceilings.md b/book/en/src/internals/ceilings.md
index 49d248adf3..07bd0adda0 100644
--- a/book/en/src/internals/ceilings.md
+++ b/book/en/src/internals/ceilings.md
@@ -28,7 +28,7 @@ An example to illustrate the ceiling analysis:
 
 ``` rust
 #[rtic::app(device = ..)]
-const APP: () = {
+mod app {
     struct Resources {
         // accessed by `foo` (prio = 1) and `bar` (prio = 2)
         // -> CEILING = 2
@@ -80,5 +80,5 @@ const APP: () = {
     }
 
     // ..
-};
+}
 ```
diff --git a/book/en/src/internals/critical-sections.md b/book/en/src/internals/critical-sections.md
index f95a5a7a3b..a064ad09a8 100644
--- a/book/en/src/internals/critical-sections.md
+++ b/book/en/src/internals/critical-sections.md
@@ -32,7 +32,7 @@ The example below shows the different types handed out to each task:
 
 ``` rust
 #[rtic::app(device = ..)]
-const APP: () = {
+mut app {
     struct Resources {
         #[init(0)]
         x: u64,
@@ -57,7 +57,7 @@ const APP: () = {
     }
 
     // ..
-};
+}
 ```
 
 Now let's see how these types are created by the framework.
@@ -99,7 +99,7 @@ pub mod bar {
     }
 }
 
-const APP: () = {
+mod app {
     static mut x: u64 = 0;
 
     impl rtic::Mutex for resources::x {
@@ -129,7 +129,7 @@ const APP: () = {
             // ..
         })
     }
-};
+}
 ```
 
 ## `lock`
@@ -225,7 +225,7 @@ Consider this program:
 
 ``` rust
 #[rtic::app(device = ..)]
-const APP: () = {
+mod app {
     struct Resources {
         #[init(0)]
         x: u64,
@@ -277,7 +277,7 @@ const APP: () = {
     }
 
     // ..
-};
+}
 ```
 
 The code generated by the framework looks like this:
@@ -315,7 +315,7 @@ pub mod foo {
     }
 }
 
-const APP: () = {
+mod app {
     use cortex_m::register::basepri;
 
     #[no_mangle]
@@ -368,7 +368,7 @@ const APP: () = {
     }
 
     // repeat for resource `y`
-};
+}
 ```
 
 At the end the compiler will optimize the function `foo` into something like
@@ -430,7 +430,7 @@ handler through preemption. This is best observed in the following example:
 
 ``` rust
 #[rtic::app(device = ..)]
-const APP: () = {
+mod app {
     struct Resources {
         #[init(0)]
         x: u64,
@@ -484,7 +484,7 @@ const APP: () = {
         // ..
     }
 
-};
+}
 ```
 
 IMPORTANT: let's say we *forget* to roll back `BASEPRI` in `UART1` -- this would
@@ -493,7 +493,7 @@ be a bug in the RTIC code generator.
 ``` rust
 // code generated by RTIC
 
-const APP: () = {
+mod app {
     // ..
 
     #[no_mangle]
@@ -513,7 +513,7 @@ const APP: () = {
         // BUG: FORGOT to roll back the BASEPRI to the snapshot value we took before
         basepri::write(initial);
     }
-};
+}
 ```
 
 The consequence is that `idle` will run at a dynamic priority of `2` and in fact
diff --git a/book/en/src/internals/interrupt-configuration.md b/book/en/src/internals/interrupt-configuration.md
index 278707c0ad..7aec9c9f4d 100644
--- a/book/en/src/internals/interrupt-configuration.md
+++ b/book/en/src/internals/interrupt-configuration.md
@@ -13,7 +13,7 @@ This example gives you an idea of the code that the RTIC framework runs:
 
 ``` rust
 #[rtic::app(device = lm3s6965)]
-const APP: () = {
+mod app {
     #[init]
     fn init(c: init::Context) {
         // .. user code ..
@@ -28,7 +28,7 @@ const APP: () = {
     fn foo(c: foo::Context) {
         // .. user code ..
     }
-};
+}
 ```
 
 The framework generates an entry point that looks like this:
diff --git a/book/en/src/internals/late-resources.md b/book/en/src/internals/late-resources.md
index ad2a5e51ed..f3a0b0ae2a 100644
--- a/book/en/src/internals/late-resources.md
+++ b/book/en/src/internals/late-resources.md
@@ -10,7 +10,7 @@ initialize late resources.
 
 ``` rust
 #[rtic::app(device = ..)]
-const APP: () = {
+mod app {
     struct Resources {
         x: Thing,
     }
@@ -34,7 +34,7 @@ const APP: () = {
     }
 
     // ..
-};
+}
 ```
 
 The code generated by the framework looks like this:
@@ -69,7 +69,7 @@ pub mod foo {
 }
 
 /// Implementation details
-const APP: () = {
+mod app {
     // uninitialized static
     static mut x: MaybeUninit<Thing> = MaybeUninit::uninit();
 
@@ -101,7 +101,7 @@ const APP: () = {
             // ..
         })
     }
-};
+}
 ```
 
 An important detail here is that `interrupt::enable` behaves like a *compiler
diff --git a/book/en/src/internals/non-reentrancy.md b/book/en/src/internals/non-reentrancy.md
index 0b0e4a7342..17b34d0ca9 100644
--- a/book/en/src/internals/non-reentrancy.md
+++ b/book/en/src/internals/non-reentrancy.md
@@ -12,7 +12,7 @@ are discouraged from directly invoking an interrupt handler.
 
 ``` rust
 #[rtic::app(device = ..)]
-const APP: () = {
+mod app {
     #[init]
     fn init(c: init::Context) { .. }
 
@@ -39,7 +39,7 @@ const APP: () = {
         // in aliasing of the static variable `X`
         unsafe { UART0() }
     }
-};
+}
 ```
 
 The RTIC framework must generate the interrupt handler code that calls the user
@@ -57,7 +57,7 @@ fn bar(c: bar::Context) {
     // .. user code ..
 }
 
-const APP: () = {
+mod app {
     // everything in this block is not visible to user code
 
     #[no_mangle]
@@ -69,7 +69,7 @@ const APP: () = {
     unsafe fn USART1() {
         bar(..);
     }
-};
+}
 ```
 
 ## By hardware
diff --git a/book/en/src/internals/tasks.md b/book/en/src/internals/tasks.md
index 995a88577b..a533dc0c26 100644
--- a/book/en/src/internals/tasks.md
+++ b/book/en/src/internals/tasks.md
@@ -28,7 +28,7 @@ Consider this example:
 
 ``` rust
 #[rtic::app(device = ..)]
-const APP: () = {
+mod app {
     // ..
 
     #[interrupt(binds = UART0, priority = 2, spawn = [bar, baz])]
@@ -51,7 +51,7 @@ const APP: () = {
     extern "C" {
         fn UART1();
     }
-};
+}
 ```
 
 The framework produces the following task dispatcher which consists of an
@@ -62,7 +62,7 @@ fn bar(c: bar::Context) {
     // .. user code ..
 }
 
-const APP: () = {
+mod app {
     use heapless::spsc::Queue;
     use cortex_m::register::basepri;
 
@@ -110,7 +110,7 @@ const APP: () = {
         // BASEPRI invariant
         basepri::write(snapshot);
     }
-};
+}
 ```
 
 ## Spawning a task
@@ -144,7 +144,7 @@ mod foo {
     }
 }
 
-const APP: () = {
+mod app {
     // ..
 
     // Priority ceiling for the producer endpoint of the `RQ1`
@@ -194,7 +194,7 @@ const APP: () = {
             }
         }
     }
-};
+}
 ```
 
 Using `bar_FQ` to limit the number of `bar` tasks that can be spawned may seem
@@ -211,7 +211,7 @@ fn baz(c: baz::Context, input: u64) {
     // .. user code ..
 }
 
-const APP: () = {
+mod app {
     // ..
 
     // Now we show the full contents of the `Ready` struct
@@ -263,13 +263,13 @@ const APP: () = {
             }
         }
     }
-};
+}
 ```
 
 And now let's look at the real implementation of the task dispatcher:
 
 ``` rust
-const APP: () = {
+mod app {
     // ..
 
     #[no_mangle]
@@ -304,7 +304,7 @@ const APP: () = {
         // BASEPRI invariant
         basepri::write(snapshot);
     }
-};
+}
 ```
 
 `INPUTS` plus `FQ`, the free queue, is effectively a memory pool. However,
@@ -357,7 +357,7 @@ Consider the following example:
 
 ``` rust
 #[rtic::app(device = ..)]
-const APP: () = {
+mod app {
     #[idle(spawn = [foo, bar])]
     fn idle(c: idle::Context) -> ! {
         // ..
@@ -382,7 +382,7 @@ const APP: () = {
     fn quux(c: quux::Context) {
         // ..
     }
-};
+}
 ```
 
 This is how the ceiling analysis would go:
diff --git a/book/en/src/internals/timer-queue.md b/book/en/src/internals/timer-queue.md
index 0eba106904..fcd345c51a 100644
--- a/book/en/src/internals/timer-queue.md
+++ b/book/en/src/internals/timer-queue.md
@@ -12,7 +12,7 @@ Let's see how this in implemented in code. Consider the following program:
 
 ``` rust
 #[rtic::app(device = ..)]
-const APP: () = {
+mod app {
     // ..
 
     #[task(capacity = 2, schedule = [foo])]
@@ -24,7 +24,7 @@ const APP: () = {
     extern "C" {
         fn UART0();
     }
-};
+}
 ```
 
 ## `schedule`
@@ -46,7 +46,7 @@ mod foo {
     }
 }
 
-const APP: () = {
+mod app {
     type Instant = <path::to::user::monotonic::timer as rtic::Monotonic>::Instant;
 
     // all tasks that can be `schedule`-d
@@ -100,7 +100,7 @@ const APP: () = {
             }
         }
     }
-};
+}
 ```
 
 This looks very similar to the `Spawn` implementation. In fact, the same
@@ -123,7 +123,7 @@ is up.
 Let's see the associated code.
 
 ``` rust
-const APP: () = {
+mod app {
     #[no_mangle]
     fn SysTick() {
         const PRIORITY: u8 = 1;
@@ -146,7 +146,7 @@ const APP: () = {
             }
         }
     }
-};
+}
 ```
 
 This looks similar to a task dispatcher except that instead of running the
@@ -197,7 +197,7 @@ able to insert the task in the timer queue; this lets us omit runtime checks.
 
 ## System timer priority
 
-The priority of the system timer can't set by the user; it is chosen by the
+The priority of the system timer can't be set by the user; it is chosen by the
 framework. To ensure that lower priority tasks don't prevent higher priority
 tasks from running we choose the priority of the system timer to be the maximum
 of all the `schedule`-able tasks.
@@ -222,7 +222,7 @@ To illustrate, consider the following example:
 
 ``` rust
 #[rtic::app(device = ..)]
-const APP: () = {
+mod app {
     #[task(priority = 3, spawn = [baz])]
     fn foo(c: foo::Context) {
         // ..
@@ -237,7 +237,7 @@ const APP: () = {
     fn baz(c: baz::Context) {
         // ..
     }
-};
+}
 ```
 
 The ceiling analysis would go like this:
@@ -246,7 +246,7 @@ The ceiling analysis would go like this:
   `SysTick` must run at the highest priority between these two, that is `3`.
 
 - `foo::Spawn` (prio = 3) and `bar::Schedule` (prio = 2) contend over the
-  consumer endpoind of `baz_FQ`; this leads to a priority ceiling of `3`.
+  consumer endpoint of `baz_FQ`; this leads to a priority ceiling of `3`.
 
 - `bar::Schedule` (prio = 2) has exclusive access over the consumer endpoint of
 `foo_FQ`; thus the priority ceiling of `foo_FQ` is effectively `2`.
@@ -270,7 +270,7 @@ run; this `Instant` is read in the task dispatcher and passed to the user code
 as part of the task context.
 
 ``` rust
-const APP: () = {
+mod app {
     // ..
 
     #[no_mangle]
@@ -303,7 +303,7 @@ const APP: () = {
         // BASEPRI invariant
         basepri::write(snapshot);
     }
-};
+}
 ```
 
 Conversely, the `spawn` implementation needs to write a value to the `INSTANTS`
@@ -333,7 +333,7 @@ mod foo {
     }
 }
 
-const APP: () = {
+mod app {
     impl<'a> foo::Spawn<'a> {
         /// Spawns the `baz` task
         pub fn baz(&self, message: u64) -> Result<(), u64> {
@@ -364,5 +364,5 @@ const APP: () = {
             }
         }
     }
-};
+}
 ```
diff --git a/book/en/src/migration.md b/book/en/src/migration.md
index 6cca64dba4..ab45c29508 100644
--- a/book/en/src/migration.md
+++ b/book/en/src/migration.md
@@ -1,14 +1,81 @@
-# Migrating from v0.4.x to v0.5.0
+# Migration of RTIC
+
+## Migrating from v0.5.x to v0.6.0
+
+This section describes how to upgrade from v0.5.x to v0.6.0 of the RTIC framework.
+
+### `Cargo.toml` - version bump
+
+Change the version of `cortex-m-rtic` to `"0.6.0"`.
+
+### Module instead of Const
+
+With the support of attributes on modules the `const APP` workaround is not needed.
+
+Change
+
+``` rust
+#[rtic::app(/* .. */)]
+const APP: () = {
+  [code here]
+};
+```
+
+into
+
+``` rust
+#[rtic::app(/* .. */)]
+mod app {
+  [code here]
+}
+```
+
+Now that a regular Rust module is used it means it is possible to have custom
+user code within that module.
+Additionally, it means that `use`-statements for resources etc may be required.
+
+### Init always returns late resources
+
+In order to make the API more symmetric the #[init]-task always returns a late resource.
+
+From this:
+
+``` rust
+#[rtic::app(device = lm3s6965)]
+mod app {
+    #[init]
+    fn init(_: init::Context) {
+        rtic::pend(Interrupt::UART0);
+    }
+    [more code]
+}
+```
+
+to this:
+
+``` rust
+#[rtic::app(device = lm3s6965)]
+mod app {
+    #[init]
+    fn init(_: init::Context) -> init::LateResources {
+        rtic::pend(Interrupt::UART0);
+
+        init::LateResources {}
+    }
+    [more code]
+}
+```
+
+## Migrating from v0.4.x to v0.5.0
 
 This section covers how to upgrade an application written against RTIC v0.4.x to
 the version v0.5.0 of the framework.
 
-## `Cargo.toml`
+### `Cargo.toml`
 
 First, the version of the `cortex-m-rtic` dependency needs to be updated to
 `"0.5.0"`. The `timer-queue` feature needs to be removed.
 
-
 ``` toml
 [dependencies.cortex-m-rtic]
 # change this
@@ -22,7 +89,7 @@ features = ["timer-queue"]
 #           ^^^^^^^^^^^^^
 ```
 
-## `Context` argument
+### `Context` argument
 
 All functions inside the `#[rtic::app]` item need to take as first argument a
 `Context` structure. This `Context` type will contain the variables that were
@@ -74,7 +141,7 @@ const APP: () = {
 };
 ```
 
-## Resources
+### Resources
 
 The syntax used to declare resources has been changed from `static mut`
 variables to a `struct Resources`.
@@ -98,7 +165,7 @@ const APP: () = {
 };
 ```
 
-## Device peripherals
+### Device peripherals
 
 If your application was accessing the device peripherals in `#[init]` through
 the `device` variable then you'll need to add `peripherals = true` to the
@@ -136,7 +203,7 @@ const APP: () = {
 };
 ```
 
-## `#[interrupt]` and `#[exception]`
+### `#[interrupt]` and `#[exception]`
 
 The `#[interrupt]` and `#[exception]` attributes have been removed. To declare
 hardware tasks in v0.5.x use the `#[task]` attribute with the `binds` argument.
@@ -182,7 +249,7 @@ const APP: () = {
 };
 ```
 
-## `schedule`
+### `schedule`
 
 The `timer-queue` feature has been removed. To use the `schedule` API one must
 first define the monotonic timer the runtime will use using the `monotonic`
@@ -194,7 +261,7 @@ Also, the `Duration` and `Instant` types and the `U32Ext` trait have been moved
 into the `rtic::cyccnt` module. This module is only available on ARMv7-M+
 devices. The removal of the `timer-queue` also brings back the `DWT` peripheral
 inside the core peripherals struct, this will need to be enabled by the application
-inside `init`. 
+inside `init`.
 
 Change this: