diff --git a/lib/budget_tracker/accounts/user.ex b/lib/budget_tracker/accounts/user.ex
index 699cf78..5866ded 100644
--- a/lib/budget_tracker/accounts/user.ex
+++ b/lib/budget_tracker/accounts/user.ex
@@ -1,4 +1,5 @@
 defmodule BudgetTracker.Accounts.User do
+  @moduledoc false
   use Ecto.Schema
   import Ecto.Changeset
   alias BudgetTracker.{DebitAccounts.DebitAccount, Operations.Operation}
diff --git a/lib/budget_tracker/accounts/user_notifier.ex b/lib/budget_tracker/accounts/user_notifier.ex
index ad958d3..102fdb8 100644
--- a/lib/budget_tracker/accounts/user_notifier.ex
+++ b/lib/budget_tracker/accounts/user_notifier.ex
@@ -1,4 +1,5 @@
 defmodule BudgetTracker.Accounts.UserNotifier do
+  @moduledoc false
   import Swoosh.Email
 
   alias BudgetTracker.Mailer
diff --git a/lib/budget_tracker/accounts/user_token.ex b/lib/budget_tracker/accounts/user_token.ex
index 59c72dd..18c7a2d 100644
--- a/lib/budget_tracker/accounts/user_token.ex
+++ b/lib/budget_tracker/accounts/user_token.ex
@@ -1,4 +1,5 @@
 defmodule BudgetTracker.Accounts.UserToken do
+  @moduledoc false
   use Ecto.Schema
   import Ecto.Query
   alias BudgetTracker.Accounts.UserToken
diff --git a/lib/budget_tracker/currencies/currency.ex b/lib/budget_tracker/currencies/currency.ex
index 25e93db..f539832 100644
--- a/lib/budget_tracker/currencies/currency.ex
+++ b/lib/budget_tracker/currencies/currency.ex
@@ -1,4 +1,7 @@
 defmodule BudgetTracker.Currencies.Currency do
+  @moduledoc """
+  Money currency in common sense.
+  """
   use Ecto.Schema
   import Ecto.Changeset
   alias BudgetTracker.{DebitAccounts.DebitAccount, Operations.Operation}
diff --git a/lib/budget_tracker/debit_accounts/debit_account.ex b/lib/budget_tracker/debit_accounts/debit_account.ex
index e6facb4..d760aac 100644
--- a/lib/budget_tracker/debit_accounts/debit_account.ex
+++ b/lib/budget_tracker/debit_accounts/debit_account.ex
@@ -1,4 +1,8 @@
 defmodule BudgetTracker.DebitAccounts.DebitAccount do
+  @moduledoc """
+  Debit account shows current amount of money in proper currency.
+  User can have multiple debit accounts, of course.
+  """
   alias BudgetTracker.{Currencies.Currency, Accounts.User, Operations.Operation}
   use Ecto.Schema
   import Ecto.Changeset
diff --git a/lib/budget_tracker/operation_categories/operation_category.ex b/lib/budget_tracker/operation_categories/operation_category.ex
index c2afeaa..93492da 100644
--- a/lib/budget_tracker/operation_categories/operation_category.ex
+++ b/lib/budget_tracker/operation_categories/operation_category.ex
@@ -1,4 +1,7 @@
 defmodule BudgetTracker.OperationCategories.OperationCategory do
+  @moduledoc """
+    Category helps to separate operations by purpose and target of payment.
+  """
   use Ecto.Schema
   import Ecto.Changeset
   alias BudgetTracker.Operations.Operation
diff --git a/lib/budget_tracker/operations/operation.ex b/lib/budget_tracker/operations/operation.ex
index c559ce2..a03898e 100644
--- a/lib/budget_tracker/operations/operation.ex
+++ b/lib/budget_tracker/operations/operation.ex
@@ -1,4 +1,10 @@
 defmodule BudgetTracker.Operations.Operation do
+  @moduledoc """
+    Model of operation with money.
+    Income is an operation with type :increase
+    Payment is an operation with type :descrease
+    Transfer from one debit account to another is a transaction of two: income + payment.
+  """
   use Ecto.Schema
   import Ecto.Changeset
 
diff --git a/lib/budget_tracker_web/components/mishka_components.ex b/lib/budget_tracker_web/components/mishka_components.ex
index 30ea7bb..1bf6252 100644
--- a/lib/budget_tracker_web/components/mishka_components.ex
+++ b/lib/budget_tracker_web/components/mishka_components.ex
@@ -1,4 +1,8 @@
 defmodule BudgetTrackerWeb.Components.MishkaComponents do
+  @moduledoc """
+    Import of Miska Component UI library
+    See details: https://mishka.tools/chelekom/docs
+  """
   defmacro __using__(_) do
     quote do
       import BudgetTrackerWeb.Components.Accordion, only: [accordion: 1, native_accordion: 1]
diff --git a/lib/budget_tracker_web/live/accounts_live/components/account_card.ex b/lib/budget_tracker_web/live/accounts_live/components/account_card.ex
index 8a58c43..1b70efb 100644
--- a/lib/budget_tracker_web/live/accounts_live/components/account_card.ex
+++ b/lib/budget_tracker_web/live/accounts_live/components/account_card.ex
@@ -1,4 +1,7 @@
 defmodule BudgetTrackerWeb.AccountsLive.Components.AccountCard do
+  @moduledoc """
+    LiveComponent for Debit Account Card
+  """
   use BudgetTrackerWeb, :live_component
 
   @income_event "income_event"
diff --git a/lib/budget_tracker_web/user_auth.ex b/lib/budget_tracker_web/user_auth.ex
index c6521b0..d70dd6a 100644
--- a/lib/budget_tracker_web/user_auth.ex
+++ b/lib/budget_tracker_web/user_auth.ex
@@ -1,4 +1,5 @@
 defmodule BudgetTrackerWeb.UserAuth do
+  @moduledoc false
   use BudgetTrackerWeb, :verified_routes
 
   import Plug.Conn