diff --git a/lib/aprsme_web/components/core_components.ex b/lib/aprsme_web/components/core_components.ex
index 319574d..f7c5c5a 100644
--- a/lib/aprsme_web/components/core_components.ex
+++ b/lib/aprsme_web/components/core_components.ex
@@ -441,6 +441,7 @@ defmodule AprsmeWeb.CoreComponents do
   Renders a modern site header with navigation links.
   """
   attr :class, :string, default: ""
+  attr :dev_mode, :boolean, default: false
 
   def header(assigns) do
     ~H"""
@@ -448,6 +449,9 @@ defmodule AprsmeWeb.CoreComponents do
       <div class="navbar-start">
         <.link navigate="/" class="btn btn-ghost text-xl font-bold text-primary">
           aprs.me
+          <%= if @dev_mode do %>
+            <span class="badge badge-warning badge-sm ml-2">DEV</span>
+          <% end %>
         </.link>
       </div>
       <div class="navbar-center hidden lg:flex">
diff --git a/lib/aprsme_web/components/layouts/app.html.heex b/lib/aprsme_web/components/layouts/app.html.heex
index df6a966..8e8c9c0 100644
--- a/lib/aprsme_web/components/layouts/app.html.heex
+++ b/lib/aprsme_web/components/layouts/app.html.heex
@@ -169,7 +169,7 @@
   }
 </style>
 
-<.header />
+<.header dev_mode={Application.get_env(:aprsme, :dev_routes, false)} />
 <main class="min-h-screen bg-base-100">
   <div>
     <.flash kind={:info} title="Success!" flash={@flash} />
diff --git a/lib/aprsme_web/live/info_live/show.ex b/lib/aprsme_web/live/info_live/show.ex
index 60c2495..8ff03d4 100644
--- a/lib/aprsme_web/live/info_live/show.ex
+++ b/lib/aprsme_web/live/info_live/show.ex
@@ -20,7 +20,9 @@ defmodule AprsmeWeb.InfoLive.Show do
 
     packet = get_latest_packet(normalized_callsign)
     packet = enrich_packet_with_device_info(packet)
-    neighbors = get_neighbors(packet, normalized_callsign)
+    # Get locale from socket assigns (set by LocaleHook)
+    locale = Map.get(socket.assigns, :locale, "en")
+    neighbors = get_neighbors(packet, normalized_callsign, locale)
     has_weather_packets = PacketUtils.has_weather_packets?(normalized_callsign)
     other_ssids = get_other_ssids(normalized_callsign)
 
@@ -43,7 +45,9 @@ defmodule AprsmeWeb.InfoLive.Show do
       # Refresh data when new packet arrives
       packet = get_latest_packet(socket.assigns.callsign)
       packet = enrich_packet_with_device_info(packet)
-      neighbors = get_neighbors(packet, socket.assigns.callsign)
+      # Get locale from socket assigns
+      locale = Map.get(socket.assigns, :locale, "en")
+      neighbors = get_neighbors(packet, socket.assigns.callsign, locale)
       has_weather_packets = PacketUtils.has_weather_packets?(socket.assigns.callsign)
       other_ssids = get_other_ssids(socket.assigns.callsign)
 
@@ -93,9 +97,9 @@ defmodule AprsmeWeb.InfoLive.Show do
     |> Map.put(:device_class, class)
   end
 
-  defp get_neighbors(nil, _callsign), do: []
+  defp get_neighbors(nil, _callsign, _locale), do: []
 
-  defp get_neighbors(packet, callsign) do
+  defp get_neighbors(packet, callsign, locale) do
     lat = packet.lat
     lon = packet.lon
 
@@ -122,7 +126,7 @@ defmodule AprsmeWeb.InfoLive.Show do
 
         %{
           callsign: p.sender,
-          distance: format_distance(dist),
+          distance: format_distance(dist, locale),
           course: course,
           last_heard: format_timestamp_for_display(p),
           packet: p
@@ -148,7 +152,7 @@ defmodule AprsmeWeb.InfoLive.Show do
     |> Enum.reverse()
   end
 
-  defp haversine(lat1, lon1, lat2, lon2) do
+  def haversine(lat1, lon1, lat2, lon2) do
     # Returns distance in km
     # Convert Decimal to float if needed
     lat1 = to_float(lat1)
@@ -215,15 +219,30 @@ defmodule AprsmeWeb.InfoLive.Show do
     end
   end
 
-  defp format_distance(km) when km < 1.0 do
-    "#{Float.round(km * 1000, 0)} m"
+  def format_distance(km, locale \\ "en") do
+    case locale do
+      "en" ->
+        # Use imperial units for English locale
+        miles = Aprsme.Convert.kph_to_mph(km)
+
+        if miles < 1.0 do
+          feet = miles * 5280
+          "#{Float.round(feet, 0)} ft"
+        else
+          "#{Float.round(miles, 2)} mi"
+        end
+
+      _ ->
+        # Use metric units for other locales
+        if km < 1.0 do
+          "#{Float.round(km * 1000, 0)} m"
+        else
+          "#{Float.round(km, 2)} km"
+        end
+    end
   end
 
-  defp format_distance(km) do
-    "#{Float.round(km, 2)} km"
-  end
-
-  defp calculate_course(lat1, lon1, lat2, lon2) do
+  def calculate_course(lat1, lon1, lat2, lon2) do
     # Calculate bearing from point 1 to point 2
     # Convert Decimal to float if needed
     lat1 = to_float(lat1)
diff --git a/lib/aprsme_web/live/info_live/show.html.heex b/lib/aprsme_web/live/info_live/show.html.heex
index 72340e1..535a371 100644
--- a/lib/aprsme_web/live/info_live/show.html.heex
+++ b/lib/aprsme_web/live/info_live/show.html.heex
@@ -336,10 +336,11 @@
                               ssid_info.packet.lat,
                               ssid_info.packet.lon
                             ) %>
+                          <% locale = Map.get(assigns, :locale, "en") %>
                           <%= if course do %>
-                            {format_distance(dist)} @ {Float.round(course, 0)}°
+                            {format_distance(dist, locale)} @ {Float.round(course, 0)}°
                           <% else %>
-                            {format_distance(dist)}
+                            {format_distance(dist, locale)}
                           <% end %>
                         <% else %>
                           -