diff --git a/pkg/app/app.go b/pkg/app/app.go
index e423359..1de26ce 100644
--- a/pkg/app/app.go
+++ b/pkg/app/app.go
@@ -17,6 +17,7 @@ import (
 	"github.com/wybiral/tube/pkg/media"
 )
 
+// App represents main application.
 type App struct {
 	Config    *Config
 	Library   *media.Library
@@ -26,6 +27,7 @@ type App struct {
 	Router    *mux.Router
 }
 
+// NewApp returns a new instance of App from Config.
 func NewApp(cfg *Config) (*App, error) {
 	if cfg == nil {
 		cfg = DefaultConfig()
@@ -33,24 +35,30 @@ func NewApp(cfg *Config) (*App, error) {
 	a := &App{
 		Config: cfg,
 	}
+	// Setup Library
 	a.Library = media.NewLibrary()
+	// Setup Watcher
 	w, err := fsnotify.NewWatcher()
 	if err != nil {
 		return nil, err
 	}
 	a.Watcher = w
+	// Setup Listener
 	ln, err := newListener(cfg.Server)
 	if err != nil {
 		return nil, err
 	}
 	a.Listener = ln
+	// Setup Templates
 	a.Templates = template.Must(template.ParseGlob("templates/*"))
+	// Setup Router
 	r := mux.NewRouter().StrictSlash(true)
 	r.HandleFunc("/", a.indexHandler).Methods("GET")
 	r.HandleFunc("/v/{id}.mp4", a.videoHandler).Methods("GET")
 	r.HandleFunc("/t/{id}", a.thumbHandler).Methods("GET")
 	r.HandleFunc("/v/{id}", a.pageHandler).Methods("GET")
 	r.HandleFunc("/feed.xml", a.rssHandler).Methods("GET")
+	// Static file handler
 	fsHandler := http.StripPrefix(
 		"/static/",
 		http.FileServer(http.Dir("./static/")),
@@ -60,6 +68,7 @@ func NewApp(cfg *Config) (*App, error) {
 	return a, nil
 }
 
+// Run imports the library and starts server.
 func (a *App) Run() error {
 	path := a.Config.LibraryPath
 	err := a.Library.Import(path)
@@ -71,6 +80,7 @@ func (a *App) Run() error {
 	return http.Serve(a.Listener, a.Router)
 }
 
+// Watch the library path and update Library with changes.
 func (a *App) watch() {
 	for {
 		e, ok := <-a.Watcher.Events
@@ -92,6 +102,7 @@ func (a *App) watch() {
 	}
 }
 
+// HTTP handler for /
 func (a *App) indexHandler(w http.ResponseWriter, r *http.Request) {
 	log.Printf("/")
 	pl := a.Library.Playlist()
@@ -108,6 +119,7 @@ func (a *App) indexHandler(w http.ResponseWriter, r *http.Request) {
 	}
 }
 
+// HTTP handler for /v/id
 func (a *App) pageHandler(w http.ResponseWriter, r *http.Request) {
 	vars := mux.Vars(r)
 	id := vars["id"]
@@ -133,6 +145,7 @@ func (a *App) pageHandler(w http.ResponseWriter, r *http.Request) {
 	})
 }
 
+// HTTP handler for /v/id.mp4
 func (a *App) videoHandler(w http.ResponseWriter, r *http.Request) {
 	vars := mux.Vars(r)
 	id := vars["id"]
@@ -149,6 +162,7 @@ func (a *App) videoHandler(w http.ResponseWriter, r *http.Request) {
 	http.ServeFile(w, r, path)
 }
 
+// HTTP handler for /t/id
 func (a *App) thumbHandler(w http.ResponseWriter, r *http.Request) {
 	vars := mux.Vars(r)
 	id := vars["id"]
@@ -167,6 +181,7 @@ func (a *App) thumbHandler(w http.ResponseWriter, r *http.Request) {
 	}
 }
 
+// HTTP handler for /feed.xml
 func (a *App) rssHandler(w http.ResponseWriter, r *http.Request) {
 	cfg := a.Config.Feed
 	now := time.Now()
diff --git a/pkg/app/config.go b/pkg/app/config.go
index 12cf21d..f8ca2e8 100644
--- a/pkg/app/config.go
+++ b/pkg/app/config.go
@@ -5,17 +5,20 @@ import (
 	"os"
 )
 
+// Config settings for main App.
 type Config struct {
 	LibraryPath string        `json:"library"`
 	Server      *ServerConfig `json:"server"`
 	Feed        *FeedConfig   `json:"feed"`
 }
 
+// ServerConfig settings for App Server.
 type ServerConfig struct {
 	Host string `json:"host"`
 	Port int    `json:"port"`
 }
 
+// FeedConfig settings for App Feed.
 type FeedConfig struct {
 	ExternalURL string `json:"external_url"`
 	Title       string `json:"title"`
@@ -28,6 +31,7 @@ type FeedConfig struct {
 	Copyright string `json:"copyright"`
 }
 
+// DefaultConfig returns Config initialized with default values.
 func DefaultConfig() *Config {
 	return &Config{
 		LibraryPath: "videos",
@@ -41,6 +45,7 @@ func DefaultConfig() *Config {
 	}
 }
 
+// ReadFile reads a JSON file into Config.
 func (c *Config) ReadFile(path string) error {
 	f, err := os.Open(path)
 	if err != nil {
diff --git a/pkg/app/listener.go b/pkg/app/listener.go
index 7d42290..a4236d8 100644
--- a/pkg/app/listener.go
+++ b/pkg/app/listener.go
@@ -1,3 +1,7 @@
+// Instead of using the default new.Listener this file will construct a custom
+// one. The main purpose for this is to have more control over the settings
+// (like keep-alive) and to retrieve the assigned port when using port 0.
+
 package app
 
 import (
diff --git a/pkg/media/library.go b/pkg/media/library.go
index 337907d..c0d79eb 100644
--- a/pkg/media/library.go
+++ b/pkg/media/library.go
@@ -9,11 +9,13 @@ import (
 	"sync"
 )
 
+// Library manages importing and retrieving video data.
 type Library struct {
 	mu     sync.RWMutex
 	Videos map[string]*Video
 }
 
+// NewLibrary returns new instance of Library.
 func NewLibrary() *Library {
 	lib := &Library{
 		Videos: make(map[string]*Video),
@@ -21,6 +23,7 @@ func NewLibrary() *Library {
 	return lib
 }
 
+// Import adds all valid videos from a given path.
 func (lib *Library) Import(path string) error {
 	files, err := ioutil.ReadDir(path)
 	if err != nil {
@@ -36,6 +39,7 @@ func (lib *Library) Import(path string) error {
 	return nil
 }
 
+// Add adds a single video from a given file path.
 func (lib *Library) Add(path string) error {
 	v, err := ParseVideo(path)
 	if err != nil {
@@ -48,6 +52,7 @@ func (lib *Library) Add(path string) error {
 	return nil
 }
 
+// Remove removes a single video from a given file path.
 func (lib *Library) Remove(path string) {
 	name := filepath.Base(path)
 	// ID is name without extension
@@ -65,6 +70,7 @@ func (lib *Library) Remove(path string) {
 	}
 }
 
+// Playlist returns a sorted Playlist of all videos.
 func (lib *Library) Playlist() Playlist {
 	lib.mu.RLock()
 	defer lib.mu.RUnlock()
diff --git a/pkg/media/playlist.go b/pkg/media/playlist.go
index 86dcb76..cf8edcf 100644
--- a/pkg/media/playlist.go
+++ b/pkg/media/playlist.go
@@ -1,15 +1,19 @@
 package media
 
+// Playlist holds an array of videos capable of sorting by Timestamp.
 type Playlist []*Video
 
+// Len returns length of array (for sorting).
 func (p Playlist) Len() int {
 	return len(p)
 }
 
+// Swap swaps two values in array by index (for sorting).
 func (p Playlist) Swap(i, j int) {
 	p[i], p[j] = p[j], p[i]
 }
 
+// Less returns true if p[i] Timestamp is after p[j] (for sorting).
 func (p Playlist) Less(i, j int) bool {
 	return p[i].Timestamp.After(p[j].Timestamp)
 }
diff --git a/pkg/media/video.go b/pkg/media/video.go
index 2499433..90ec595 100644
--- a/pkg/media/video.go
+++ b/pkg/media/video.go
@@ -8,6 +8,7 @@ import (
 	"github.com/dhowden/tag"
 )
 
+// Video represents metadata for a single video.
 type Video struct {
 	ID          string
 	Title       string
@@ -20,6 +21,7 @@ type Video struct {
 	Timestamp   time.Time
 }
 
+// ParseVideo parses a video file's metadata and returns a Video.
 func ParseVideo(path string) (*Video, error) {
 	f, err := os.Open(path)
 	if err != nil {