A few more comments here and there.

app.c

@@ -242,8 +242,6 @@ ProtoViewApp* protoview_app_alloc() {
 
     //init Worker & Protocol
     app->txrx = malloc(sizeof(ProtoViewTxRx));
-    app->txrx->preset = malloc(sizeof(SubGhzRadioPreset));
-    app->txrx->preset->name = furi_string_alloc();
 
     /* Setup rx worker and environment. */
     app->txrx->worker = subghz_worker_alloc();
@@ -286,8 +284,6 @@ void protoview_app_free(ProtoViewApp *app) {
     subghz_receiver_free(app->txrx->receiver);
     subghz_environment_free(app->txrx->environment);
     subghz_worker_free(app->txrx->worker);
-    furi_string_free(app->txrx->preset->name);
-    free(app->txrx->preset);
     free(app->txrx);
 
     furi_hal_power_suppress_charge_exit();
@@ -313,13 +309,21 @@ int32_t protoview_app_entry(void* p) {
     FuriTimer *timer = furi_timer_alloc(timer_callback, FuriTimerTypePeriodic, app);
     furi_timer_start(timer, furi_kernel_get_tick_frequency() / 10);
 
+    /* Start listening to signals immediately. */
     radio_begin(app);
     radio_rx(app, FREQ);
 
+    /* This is the main event loop: here we get the events that are pushed
+     * in the queue by input_callback(), and process them one after the
+     * other. The timeout is 100 milliseconds, so if not input is received
+     * before such time, we exit the queue_get() function and call
+     * view_port_update() in order to refresh our screen content. */
     InputEvent input;
     while(app->running) {
         FuriStatus qstat = furi_message_queue_get(app->event_queue, &input, 100);
         if (qstat == FuriStatusOk) {
+            FURI_LOG_E(TAG, "Main Loop - Input: %u", input.key);
+
             if (input.key == InputKeyBack) {
                 app->running = 0;
             } else if (input.key == InputKeyOk) {
@@ -333,8 +337,6 @@ int32_t protoview_app_entry(void* p) {
                 uint32_t scale_step = app->us_scale > 50 ? 50 : 10;
                 if (app->us_scale > 10) app->us_scale -= scale_step;
             }
-
-            FURI_LOG_E(TAG, "Main Loop - Input: %u", input.key);
         } else {
             static int c = 0;
             c++;
@@ -343,6 +345,7 @@ int32_t protoview_app_entry(void* p) {
         view_port_update(app->view_port);
     }
 
+    /* App no longer running. Shut down and free. */
     if (app->txrx->txrx_state == TxRxStateRx) {
         FURI_LOG_E(TAG, "Putting CC1101 to sleep before exiting.");
         radio_rx_end(app);

app.h

@@ -28,21 +28,21 @@ typedef enum {
  * It receives data and we get our protocol "feed" callback called
  * with the level (1 or 0) and duration. */
 struct ProtoViewTxRx {
-    SubGhzWorker* worker;
+    SubGhzWorker* worker;       /* Our background worker. */
     SubGhzEnvironment* environment;
     SubGhzReceiver* receiver;
-    SubGhzRadioPreset* preset;
     TxRxState txrx_state; /* Receiving, idle or sleeping? */
 };
 
 typedef struct ProtoViewTxRx ProtoViewTxRx;
 
 struct ProtoViewApp {
     Gui *gui;
-    ViewPort *view_port;
-    FuriMessageQueue *event_queue;
+    ViewPort *view_port;     /* We just use a raw viewport and we render
+                                everything into the low level canvas. */
+    FuriMessageQueue *event_queue;  /* Keypress events go here. */
     ProtoViewTxRx *txrx;     /* Radio state. */
-    SubGhzSetting *setting;
+    SubGhzSetting *setting;  /* A list of valid frequencies. */
     int running;             /* Once false exists the app. */
     uint32_t signal_bestlen; /* Longest coherent signal observed so far. */
     uint32_t us_scale;       /* microseconds per pixel. */

proto.c

@@ -40,7 +40,8 @@ void subghz_protocol_decoder_protoview_reset(void* context) {
 }
 
 /* That's the only thig we really use of the protocol decoder
- * implementation. */
+ * implementation. We avoid the subghz provided abstractions and put
+ * the data in our simple abstraction: the RawSamples circular buffer. */
 void subghz_protocol_decoder_protoview_feed(void* context, bool level, uint32_t duration) {
     furi_assert(context);
     UNUSED(context);
@@ -58,6 +59,7 @@ uint8_t subghz_protocol_decoder_protoview_get_hash_data(void* context) {
     return 123;
 }
 
+/* Not used. */
 bool subghz_protocol_decoder_protoview_serialize(
     void* context,
     FlipperFormat* flipper_format,
@@ -69,6 +71,7 @@ bool subghz_protocol_decoder_protoview_serialize(
     return false;
 }
 
+/* Not used. */
 bool subghz_protocol_decoder_protoview_deserialize(void* context, FlipperFormat* flipper_format)
 {
     UNUSED(context);
@@ -93,13 +96,17 @@ const SubGhzProtocolDecoder subghz_protocol_protoview_decoder = {
     .get_string = subhz_protocol_decoder_protoview_get_string,
 };
 
+/* Well, we don't really target a specific protocol. So let's put flags
+ * that make sense. */
 const SubGhzProtocol subghz_protocol_protoview = {
     .name = "Protoview",
     .type = SubGhzProtocolTypeStatic,
-    .flag = SubGhzProtocolFlag_AM | SubGhzProtocolFlag_Decodable,
+    .flag = SubGhzProtocolFlag_AM | SubGhzProtocolFlag_FM | SubGhzProtocolFlag_Decodable,
     .decoder = &subghz_protocol_protoview_decoder,
 };
 
+/* Our table has just the single dummy protocol we defined for the
+ * sake of data collection. */
 const SubGhzProtocol* protoview_protocol_registry_items[] = {
     &subghz_protocol_protoview,
 };