diff --git a/reaction_diffusion_dynamics.py b/reaction_diffusion_dynamics.py
new file mode 100644
index 0000000..f8fd35f
--- /dev/null
+++ b/reaction_diffusion_dynamics.py
@@ -0,0 +1,335 @@
+"""
+This is a streamlit app.
+"""
+import base64
+import dataclasses
+import io
+import json
+import random
+from dataclasses import dataclass
+from typing import Optional
+
+import jax
+import matplotlib.pyplot as plt
+import numpy as np
+import streamlit as st
+import streamlit.components.v1 as components
+from IPython.display import DisplayObject
+from matplotlib.colors import Colormap, LinearSegmentedColormap, ListedColormap
+
+import exponax as ex
+
+st.set_page_config(layout="wide")
+jax.config.update("jax_platform_name", "cpu")
+
+with st.sidebar:
+    st.title("Exponax Dynamics Brewer")
+    dimension_type = st.select_slider(
+        "Number of Spatial Dimensions (ST=Spatio-Temporal plot)",
+        options=["1d ST", "1d", "2d", "2d ST", "3d"],
+    )
+    num_points = st.slider("Number of points", 16, 256, 48)
+    num_steps = st.slider("Number of steps", 1, 300, 50)
+    num_modes_init = st.slider(
+        "Number of modes in the initial condition (not GS)", 1, 40, 5
+    )
+    num_substeps = st.slider("Number of substeps", 1, 100, 1)
+
+    v_range = st.slider("Value range", 0.1, 10.0, 1.0)
+
+    st.divider()
+
+    rd_type = st.select_slider(
+        "Type of Equation", ["FisherKPP", "GrayScott", "SwiftHohenberg"]
+    )
+
+    domain_extent_cols = st.columns(3)
+    with domain_extent_cols[0]:
+        domain_extent_mantissa = st.slider("domain_extent mantissa", 0.0, 1.0, 0.1)
+    with domain_extent_cols[1]:
+        domain_extent_exponent = st.slider("domain_extent exponent", -5, 5, 1)
+    domain_extent_sign = "+"
+    domain_extent = float(
+        f"{domain_extent_sign}{domain_extent_mantissa}e{domain_extent_exponent}"
+    )
+
+    dt_cols = st.columns(3)
+    with dt_cols[0]:
+        dt_mantissa = st.slider("dt mantissa", 0.0, 1.0, 0.5)
+    with dt_cols[1]:
+        dt_exponent = st.slider("dt exponent", -5, 5, 0)
+    dt_sign = "+"
+    dt = float(f"{dt_sign}{dt_mantissa}e{dt_exponent}")
+
+    if rd_type == "FisherKPP":
+        diffusivity_cols = st.columns(3)
+        with diffusivity_cols[0]:
+            diffusivity_mantissa = st.slider("diffusivity mantissa", 0.0, 1.0, 0.1)
+        with diffusivity_cols[1]:
+            diffusivity_exponent = st.slider("diffusivity exponent", -5, 5, -2)
+        diffusivity_sign = "+"
+        diffusivity = float(
+            f"{diffusivity_sign}{diffusivity_mantissa}e{diffusivity_exponent}"
+        )
+
+        reactivity_cols = st.columns(3)
+        with reactivity_cols[0]:
+            reactivity_mantissa = st.slider("reactivity mantissa", 0.0, 1.0, 0.1)
+        with reactivity_cols[1]:
+            reactivity_exponent = st.slider("reactivity exponent", -5, 5, 0)
+        reactivity_sign = "+"
+        reactivity = float(
+            f"{reactivity_sign}{reactivity_mantissa}e{reactivity_exponent}"
+        )
+    elif rd_type == "GrayScott":
+        feed_rate = st.slider("feed_rate", 0.00, 0.08, 0.008, 0.004, format="%.3f")
+        kill_rate = st.slider("kill_rate", 0.03, 0.07, 0.046, 0.002, format="%.3f")
+
+        st.write("Only displays the second channel")
+    elif rd_type == "SwiftHohenberg":
+        reactivity = st.slider("reactivity", 0.0, 1.0, 0.7)
+        critical_number = st.slider("critical_number", 0.0, 1.0, 1.0)
+
+    # st.write(f"dt: {dt}")
+    # st.write(f"diffusivity: {diffusivity}")
+    # st.write(f"domain_extent: {domain_extent}")
+
+    # st.write(f"Linear: {linear_tuple}")
+    # st.write(f"Nonlinear: {nonlinear_tuple}")
+
+if dimension_type in ["1d ST", "1d"]:
+    num_spatial_dims = 1
+elif dimension_type in ["2d ST", "2d"]:
+    num_spatial_dims = 2
+elif dimension_type == "3d":
+    num_spatial_dims = 3
+
+if rd_type == "FisherKPP":
+    stepper = ex.RepeatedStepper(
+        ex.reaction.FisherKPP(
+            num_spatial_dims,
+            domain_extent,
+            num_points,
+            dt / num_substeps,
+            diffusivity=diffusivity,
+            reactivity=reactivity,
+        ),
+        num_substeps,
+    )
+elif rd_type == "GrayScott":
+    stepper = ex.RepeatedStepper(
+        ex.reaction.GrayScott(
+            num_spatial_dims,
+            domain_extent,
+            num_points,
+            dt / num_substeps,
+            feed_rate=feed_rate,
+            kill_rate=kill_rate,
+        ),
+        num_substeps,
+    )
+elif rd_type == "SwiftHohenberg":
+    stepper = ex.RepeatedStepper(
+        ex.reaction.SwiftHohenberg(
+            num_spatial_dims,
+            domain_extent,
+            num_points,
+            dt / num_substeps,
+            reactivity=reactivity,
+            critical_number=critical_number,
+        ),
+        num_substeps,
+    )
+
+if rd_type == "GrayScott":
+    ic_gen = ex.ic.RandomMultiChannelICGenerator(
+        [
+            ex.ic.RandomGaussianBlobs(num_spatial_dims, one_complement=True),
+            ex.ic.RandomGaussianBlobs(num_spatial_dims),
+        ]
+    )
+else:
+    if num_spatial_dims == 1:
+        ic_gen = ex.ic.RandomSineWaves1d(
+            num_spatial_dims, cutoff=num_modes_init, max_one=True
+        )
+    else:
+        ic_gen = ex.ic.RandomTruncatedFourierSeries(
+            num_spatial_dims, cutoff=num_modes_init, max_one=True
+        )
+
+    if rd_type == "FisherKPP":
+        ic_gen = ex.ic.ClampingICGenerator(ic_gen)
+
+u_0 = ic_gen(num_points, key=jax.random.PRNGKey(0))
+
+trj = ex.rollout(stepper, num_steps, include_init=True)(u_0)
+
+if rd_type == "GrayScott":
+    trj = trj[:, 1:]
+
+
+TEMPLATE_IFRAME = """
+    <div>
+        <iframe id="{canvas_id}" src="https://keksboter.github.io/v4dv/?inline" width="{canvas_width}" height="{canvas_height}" frameBorder="0" sandbox="allow-same-origin allow-scripts"></iframe>
+    </div>
+    <script>
+
+        window.addEventListener(
+            "message",
+            (event) => {{
+                if (event.data !== "ready") {{
+                    return;
+                }}
+                let data_decoded = Uint8Array.from(atob("{data_code}"), c => c.charCodeAt(0));
+                let cmap_decoded = Uint8Array.from(atob("{cmap_code}"), c => c.charCodeAt(0));
+                const iframe = document.getElementById("{canvas_id}");
+                if (iframe === null) return;
+                iframe.contentWindow.postMessage({{
+                    volume: data_decoded,
+                    cmap: cmap_decoded,
+                    settings: {settings_json}
+                }},
+                "*");
+            }},
+            false,
+        );
+    </script>
+"""
+
+
+@dataclass(unsafe_hash=True)
+class ViewerSettings:
+    width: int
+    height: int
+    background_color: tuple
+    show_colormap_editor: bool
+    show_volume_info: bool
+    vmin: Optional[float]
+    vmax: Optional[float]
+
+
+def show(
+    data: np.ndarray,
+    colormap,
+    width: int = 800,
+    height: int = 600,
+    background_color=(0.0, 0.0, 0.0, 1.0),
+    show_colormap_editor=False,
+    show_volume_info=False,
+    vmin=None,
+    vmax=None,
+):
+    return VolumeRenderer(
+        data,
+        colormap,
+        ViewerSettings(
+            width,
+            height,
+            background_color,
+            show_colormap_editor,
+            show_volume_info,
+            vmin,
+            vmax,
+        ),
+    )
+
+
+class VolumeRenderer(DisplayObject):
+    def __init__(self, data: np.ndarray, colormap, settings: ViewerSettings):
+        super(VolumeRenderer, self).__init__(
+            data={"volume": data, "cmap": colormap, "settings": settings}
+        )
+
+    def _repr_html_(self):
+        data = self.data["volume"]
+        colormap = self.data["cmap"]
+        settings = self.data["settings"]
+        buffer = io.BytesIO()
+        np.save(buffer, data.astype(np.float32))
+        data_code = base64.b64encode(buffer.getvalue())
+
+        buffer2 = io.BytesIO()
+        colormap_data = colormap(np.linspace(0, 1, 256)).astype(np.float32)
+        np.save(buffer2, colormap_data)
+        cmap_code = base64.b64encode(buffer2.getvalue())
+
+        canvas_id = f"v4dv_canvas_{str(random.randint(0,2**32))}"
+        html_code = TEMPLATE_IFRAME.format(
+            canvas_id=canvas_id,
+            data_code=data_code.decode("utf-8"),
+            cmap_code=cmap_code.decode("utf-8"),
+            canvas_width=settings.width,
+            canvas_height=settings.height,
+            settings_json=json.dumps(dataclasses.asdict(settings)),
+        )
+        return html_code
+
+    def __html__(self):
+        """
+        This method exists to inform other HTML-using modules (e.g. Markupsafe,
+        htmltag, etc) that this object is HTML and does not need things like
+        special characters (<>&) escaped.
+        """
+        return self._repr_html_()
+
+
+def felix_cmap_hack(cmap: Colormap) -> Colormap:
+    """changes the alpha channel of a colormap to be diverging (0->1, 0.5 > 0, 1->1)
+
+    Args:
+        cmap (Colormap): colormap
+
+    Returns:
+        Colormap: new colormap
+    """
+    cmap = cmap.copy()
+    if isinstance(cmap, ListedColormap):
+        for i, a in enumerate(cmap.colors):
+            a.append(2 * abs(i / cmap.N - 0.5))
+    elif isinstance(cmap, LinearSegmentedColormap):
+        cmap._segmentdata["alpha"] = np.array(
+            [[0.0, 1.0, 1.0], [0.5, 0.0, 0.0], [1.0, 1.0, 1.0]]
+        )
+    else:
+        raise TypeError(
+            "cmap must be either a ListedColormap or a LinearSegmentedColormap"
+        )
+    return cmap
+
+
+if dimension_type == "1d ST":
+    ex.viz.plot_spatio_temporal(trj, vlim=(-v_range, v_range))
+    fig = plt.gcf()
+    st.pyplot(fig)
+elif dimension_type == "1d":
+    ani = ex.viz.animate_state_1d(trj, vlim=(-v_range, v_range))
+    components.html(ani.to_jshtml(), height=800)
+elif dimension_type == "2d":
+    ani = ex.viz.animate_state_2d(trj, vlim=(-v_range, v_range))
+    components.html(ani.to_jshtml(), height=800)
+elif dimension_type == "2d ST":
+    trj_rearranged = trj.transpose(1, 0, 2, 3)[None]
+    components.html(
+        show(
+            trj_rearranged,
+            plt.get_cmap("RdBu_r"),
+            width=1500,
+            height=800,
+            show_colormap_editor=True,
+            show_volume_info=True,
+        ).__html__(),
+        height=800,
+    )
+elif dimension_type == "3d":
+    components.html(
+        show(
+            trj,
+            plt.get_cmap("RdBu_r"),
+            width=1500,
+            height=800,
+            show_colormap_editor=True,
+            show_volume_info=True,
+        ).__html__(),
+        height=800,
+    )