diff --git a/lib/mindwendel/local_storage.ex b/lib/mindwendel/local_storage.ex
new file mode 100644
index 00000000..728097fa
--- /dev/null
+++ b/lib/mindwendel/local_storage.ex
@@ -0,0 +1,65 @@
+defmodule Mindwendel.LocalStorage do
+  alias Mindwendel.Permissions
+
+  @moduledoc """
+  The LocalStorage context. It includes helpers to handle local storage data from clients.
+  """
+
+  # This function is used to merge the brainstormings from local storage and the session.
+  # It returns a list of brainstormings sorted by the last_accessed_at field.
+  def brainstormings_from_local_storage_and_session(
+        brainstormings_from_local_storage,
+        brainstormings_from_session,
+        user
+      ) do
+    (brainstormings_from_local_storage(brainstormings_from_local_storage) ++
+       brainstormings_from_session(brainstormings_from_session, user))
+    |> Enum.uniq_by(& &1["id"])
+    |> Enum.sort(&(&1["last_accessed_at"] > &2["last_accessed_at"]))
+  end
+
+  defp brainstormings_from_local_storage(brainstormings_stored) do
+    if is_list(brainstormings_stored) do
+      brainstormings_stored
+      |> Enum.map(fn e ->
+        Map.put(e, "last_accessed_at", format_iso8601(e["last_accessed_at"]))
+      end)
+      |> Enum.filter(&valid_stored_brainstorming?/1)
+    else
+      []
+    end
+  end
+
+  defp brainstormings_from_session(brainstormings, user) do
+    Enum.map(brainstormings, fn brainstorming ->
+      %{
+        "last_accessed_at" => brainstorming.last_accessed_at,
+        "name" => brainstorming.name,
+        "id" => brainstorming.id,
+        "admin_url_id" =>
+          if(Permissions.has_moderating_permission(brainstorming, user),
+            do: brainstorming.admin_url_id,
+            else: nil
+          )
+      }
+    end)
+  end
+
+  defp valid_stored_brainstorming?(brainstorming) do
+    case Ecto.UUID.cast(brainstorming["id"]) do
+      {:ok, _} -> brainstorming["last_accessed_at"] && brainstorming["name"]
+      :error -> false
+    end
+  end
+
+  defp format_iso8601(iso8601) when iso8601 != nil do
+    case DateTime.from_iso8601(iso8601) do
+      {:ok, date_time, _} -> date_time
+      {:error, _} -> nil
+    end
+  end
+
+  defp format_iso8601(_) do
+    nil
+  end
+end
diff --git a/lib/mindwendel/permissions.ex b/lib/mindwendel/permissions.ex
new file mode 100644
index 00000000..4762d1e0
--- /dev/null
+++ b/lib/mindwendel/permissions.ex
@@ -0,0 +1,8 @@
+defmodule Mindwendel.Permissions do
+  @moduledoc """
+  The Permissions context.
+  """
+  def has_moderating_permission(brainstorming, current_user) do
+    Enum.member?(current_user.moderated_brainstormings |> Enum.map(& &1.id), brainstorming.id)
+  end
+end