diff --git a/app.py b/app.py
new file mode 100644
index 0000000..c9ed279
--- /dev/null
+++ b/app.py
@@ -0,0 +1,109 @@
+import streamlit as st
+
+
+class Moon:
+    def __init__(self, name, tier, inside_max_power, outside_max_power):
+        self.name = name
+        self.tier = tier
+        self.inside_max_power = inside_max_power
+        self.outside_max_power = outside_max_power
+
+
+class Creature:
+    def __init__(self, name, power, max_spawns, hits_to_kill):
+        self.name = name
+        self.power = power
+        self.max_spawns = max_spawns
+        self.hits_to_kill = hits_to_kill
+
+
+class Run:
+    def __init__(self, moon):
+        self.moon = moon
+
+
+def add_field():
+    st.session_state.fields_size += 1
+
+
+def delete_field(index):
+    st.session_state.fields_size -= 1
+    del st.session_state.fields[index]
+    del st.session_state.deletes[index]
+
+
+def main():
+    st.set_page_config('Scouter', '🔎')
+
+    moons = [
+        # Tier 1
+        Moon('Experimentation', 1, 4, 8),
+        Moon('Assurance', 1, 6, 8),
+        Moon('Vow', 1, 7, 6),
+        # Tier 2
+        Moon('Offense', 2, 12, 12),
+        Moon('March', 2, 14, 12),
+        # Tier 3
+        Moon('Rend', 3, 10, 6),
+        Moon('Dine', 3, 15, 6),
+        Moon('Titan', 3, 18, 7),
+    ]
+
+    outside_creatures = [
+        Creature('Baboon Hawk', 1, 15, 6),
+        Creature('Circuit Bees', 1, 6, None),
+        Creature('Eyeless Dog', 2, 8, 12),
+        Creature('Forest Keeper', 3, 3, None),
+        Creature('Earth Leviathan', 2, 3, None),
+        # Hybrid
+        Creature('Outside Ghost Girl ', 2, 1, None),
+        Creature('Outside Masked', 10, 10, 4),
+    ]
+
+    inside_creatures = [
+        Creature('Bracken', 3, 1, 6),
+        Creature('Bunker Spider', 3, 1, 6),
+        Creature('Coil Head', 1, 5, None),
+        Creature('Hoarding Bug', 1, 8, 3),
+        Creature('Hygrodere', 1, 2, None),
+        Creature('Jester', 3, 1, None),
+        Creature('Nutcracker', 1, 10, 5),
+        Creature('Snare Flea', 1, 4, 3),
+        Creature('Spore Lizard', 1, 2, None),
+        Creature('Thumper', 2, 4, 4),
+        # Hybrid
+        Creature('Inside Ghost Girl', 2, 1, None),
+        Creature('Inside Masked', 10, 10, 4),
+    ]
+
+    st.markdown('# :red[Lethal Company] Scouter')
+    st.markdown(":rainbow[What does the scouter say about this moon's power level?]")
+
+    moon = st.selectbox('Moon', sorted(m.name for m in moons),
+                        placeholder='Moon! Pick a moon!',
+                        help='Pick your current moon.')
+    run = Run(next(m for m in moons if m.name is moon))
+
+    st.markdown(f"## {run.moon.name} (Tier {run.moon.tier})")
+    column_1, column_2 = st.columns(2)
+
+    with column_1:
+        st.markdown('### Outside')
+        st.info(f"Maximum power: {run.moon.outside_max_power}")
+
+        for outside_creature in outside_creatures:
+            st.slider(outside_creature.name, 0, outside_creature.max_spawns)
+
+    with column_2:
+        st.markdown('### Inside')
+        st.info(f"Maximum power: {run.moon.inside_max_power}")
+
+        for inside_creature in inside_creatures:
+            st.slider(inside_creature.name, 0, inside_creature.max_spawns)
+
+
+# https://docs.streamlit.io/library/api-reference/session-state
+
+
+if __name__ == '__main__':
+    main()