diff --git a/README.md b/README.md
index 22fb14c..36fc097 100644
--- a/README.md
+++ b/README.md
@@ -1,7 +1,3 @@
-# Crash course on Python installation, with a few small side tracks
-
-
-
 # Installation
 1. If not already done so, create a virtual environment to contain all the packages required. Python 3.10 is recommended. The command below will create a new environment named 'app-env' with the latest version of Python 3.10.
 
@@ -13,4 +9,38 @@ conda activate app-env
 
 3. The prompt should now read '(app-env)' on the left. The app is not published on Github or anywhere else. The link below points to my own personnal home server (I didn't find any way of getting a direct download link  You are now ready to install everything with this command:
 
-pip install https://bao.dedebenui.me/s/f3KgiqMq7giN73i/download
+pip install "git+file://<path to the git repository>"
+
+# Usage
+
+1. Make sure your environment is activated (step 1 above)
+
+2. call the `dispersionapp` command
+
+dispersionapp
+
+2*. this can be also done via calling python first (`-m` tells python to open the specified module)
+
+python -m dispersionapp
+
+# Interface
+
+On the top left, you will see a summary of the current configuration. On the right, you will find the paremter list.
+
+from left to right :
+- the name of the paramter
+- a slider to quickly explore values
+- arrow buttons to move from one value to the next
+- a text box where you can input your desired value. The closest possible value will then be selected.
+- a button to automatically "play" the parameter from its current positition to its maximum
+- interval during which each parameter is displayed while playing.
+
+To navigate the plot:
+- left-click + drag to move around
+- right-click + drag to zoom
+- scroll wheel to zoom
+- for each kind of movement, you can do it while the cursor is hovering over one of the axis. In that case, only that axis is affected.
+- to go back to a view that fits everything, click on the small "A" at the bottom left.
+- to hide/show a line, click on it in the legend. You can also click+drag on the legend to move it around.
+- double click on the purple title bar (left side or top) to pop out the plot in its own window.
+
diff --git a/src/dispersionapp/gui.py b/src/dispersionapp/gui.py
index bff4837..d26b9e5 100644
--- a/src/dispersionapp/gui.py
+++ b/src/dispersionapp/gui.py
@@ -19,6 +19,7 @@ def app(config_file: os.PathLike | None = None):
     wl_ind = sc.math.argclosest(wl, config.wl_pump * 1e-9)
     w0 = w[wl_ind]
 
+
     gas = sc.materials.Gas(config.gas)
 
     with PlotApp(
@@ -31,9 +32,10 @@ def app(config_file: os.PathLike | None = None):
         t_fwhm_fs=np.arange(10, 201, dtype=float),
     ) as app:
         # initial setup
-        app[0].horizontal_line("reference", 0, color="gray")
-        app[0].set_xlabel("wavelength (nm)")
-        app[0].set_ylabel("beta2 (fs^2/cm)")
+        ax = app["Dispersion plot"]
+        ax.horizontal_line("reference", 0, color="gray")
+        ax.set_xlabel("wavelength (nm)")
+        ax.set_ylabel("beta2 (fs^2/cm)")
         if config.current_state is not None:
             app.params["core_diameter_um"].value = config.current_state.core_diameter_um
             app.params["pressure_mbar"].value = config.current_state.pressure_mbar
@@ -48,7 +50,7 @@ def app(config_file: os.PathLike | None = None):
             app.params["n_tubes"].value = 7
             app.params["gap_um"].value = 5
             app.params["t_fwhm_fs"].value = 100
-        app[0].set_lim(ylim=(-4, 2))
+        ax.set_lim(ylim=(-4, 2))
 
         app.update(config.update_current)
 
@@ -129,12 +131,12 @@ def app(config_file: os.PathLike | None = None):
             b2 = compute_vincetti(
                 wall_thickness_um, core_diameter_um, pressure_mbar, n_tubes, gap_um
             )
-            app[0].set_line_data("Vincetti", wl * 1e9, sc.units.beta2_fs_cm_inv(b2))
+            ax.set_line_data("Vincetti", wl * 1e9, sc.units.beta2_fs_cm_inv(b2))
 
         @app.update
         def draw_capillary(core_diameter_um: float, pressure_mbar: float):
             b2 = compute_capillary(core_diameter_um, pressure_mbar)
-            app[0].set_line_data("Capillary", wl * 1e9, sc.units.beta2_fs_cm_inv(b2))
+            ax.set_line_data("Capillary", wl * 1e9, sc.units.beta2_fs_cm_inv(b2))
 
         @app.update
         def draw_energy_limit(core_diameter_um: float, pressure_mbar: float, t_fwhm_fs: float):
@@ -151,7 +153,7 @@ def app(config_file: os.PathLike | None = None):
                 return
 
             zdw = lim.wl_zero_disp * 1e9
-            app[0].set_line_data("zdw", [zdw, zdw], [-3, 3])
+            ax.set_line_data("zdw", [zdw, zdw], [-3, 3])
 
             info_lines.append(f"ZDW = {zdw:.0f}nm")
             if lim.ion_lim > lim.sf_lim: