diff --git a/README.md b/README.md
index 919ccbf..d8a1c79 100644
--- a/README.md
+++ b/README.md
@@ -1 +1,67 @@
-# kOS.Utils
\ No newline at end of file
+# kOS.Utils
+## Orbital functions
+
+To access orbital functions, use ADDONS:OBT.
+Example : ADDONS:OBT:MEANANOMALYATUT(ship, 2810320).
+
+- MeanAnomalyAtUT([Orbitable](https://ksp-kos.github.io/KOS/structures/orbits/orbitable.html) obt, Scalar UT)
+  
+  The mean anomaly for the orbitable obt at the given time.
+  
+- RadiusAtTrueAnomaly([Orbitable](https://ksp-kos.github.io/KOS/structures/orbits/orbitable.html) obt, Scalar TrueAnomaly)
+
+  The orbital radius at the point in the orbit given by the true anomaly for the orbitable obt.
+
+- TrueAnomalyAtRadius([Orbitable](https://ksp-kos.github.io/KOS/structures/orbits/orbitable.html) obt, Scalar radius)
+
+  The true anomaly at the given orbital radius for the orbitable obt.
+
+- TrueAnomalyAtUT([Orbitable](https://ksp-kos.github.io/KOS/structures/orbits/orbitable.html) obt, Scalar UT)
+
+  The true anomaly at the given time for the orbitable obt.
+  
+- UTAtTrueAnomaly([Orbitable](https://ksp-kos.github.io/KOS/structures/orbits/orbitable.html) obt, Scalar TrueAnomaly)
+
+  The universal time, in seconds, corresponding to the given true anomaly, for the orbitable obt.
+  
+- EccentricAnomalyAtUT([Orbitable](https://ksp-kos.github.io/KOS/structures/orbits/orbitable.html) obt, Scalar UT)
+
+  The eccentric anomaly at the given universal time, for the orbitable obt.
+  
+- TrueAnomalyAtAN([Orbitable](https://ksp-kos.github.io/KOS/structures/orbits/orbitable.html) ship, [Orbitable](https://ksp-kos.github.io/KOS/structures/orbits/orbitable.html) target)
+
+  The true anomaly of the ascending node with the given target orbit.
+  
+- TrueAnomalyAtDN([Orbitable](https://ksp-kos.github.io/KOS/structures/orbits/orbitable.html) ship, [Orbitable](https://ksp-kos.github.io/KOS/structures/orbits/orbitable.html) target)
+
+  The true anomaly of the descending node with the given target orbit.
+
+- RelativeInclination([Orbitable](https://ksp-kos.github.io/KOS/structures/orbits/orbitable.html) ship, [Orbitable](https://ksp-kos.github.io/KOS/structures/orbits/orbitable.html) target)
+
+  Relative inclination of an orbit and another, in degrees.
+
+## Input
+
+To access input functions, use ADDONS:INPUT.
+Example : ADDONS:INPUT:ENGAGE().
+
+- Engage()
+
+  Lock the input. You MUST do this before calling GetKey.
+
+- Disengage()
+
+  Unlock the input.
+  
+- GetKey(String key)
+
+  Returns true if the key is pressed. Values for key can be found [here](https://gist.github.com/C0DEF52/b1168e6ed3d1f567fc919f2942037bab).
+  
+## Screen
+
+To access screenshot functions, use ADDONS:SCREEN.
+Example : ADDONS:SCREEN:TAKE().
+
+- Take()
+
+  Takes a screenshot and saves it in KSP/Screenshots_kOS.