diff --git a/CHANGELOG.md b/CHANGELOG.md
index 047d98b..a2c83d9 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,12 @@
 # Changelog
 
+## 0.1.4
+
+#### New Functions
+- `use_supported`
+- `use_resize_observer`
+- `watch`
+
 ## 0.1.3
 
 #### New Functions
diff --git a/Cargo.toml b/Cargo.toml
index 180bc0c..cedd725 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -14,10 +14,23 @@ repository = "https://github.com/Synphonyte/leptos-use"
 
 [dependencies]
 leptos = "0.3.0"
-web-sys = { version = "0.3.63", features = ["ScrollToOptions", "ScrollBehavior", "CssStyleDeclaration"] }
 wasm-bindgen = "0.2.86"
 js-sys = "0.3.63"
 default-struct-builder = "0.1.0"
 
+[dependencies.web-sys]
+version = "0.3.63"
+features = [
+    "ScrollToOptions",
+    "ScrollBehavior",
+    "CssStyleDeclaration",
+    "ResizeObserver",
+    "ResizeObserverOptions",
+    "ResizeObserverBoxOptions",
+    "ResizeObserverSize",
+    "ResizeObserverEntry",
+    "Navigator",
+]
+
 [features]
 docs = []
\ No newline at end of file
diff --git a/docs/book/src/SUMMARY.md b/docs/book/src/SUMMARY.md
index 2b5eb9f..8d86c14 100644
--- a/docs/book/src/SUMMARY.md
+++ b/docs/book/src/SUMMARY.md
@@ -16,7 +16,12 @@
 
 - [use_scroll](sensors/use_scroll.md)
 
+# Watch
+
+- [watch](watch/watch.md)
+
 # Utilities
 
 - [use_debounce_fn](utilities/use_debounce_fn.md)
+- [use_supported](utilities/use_supported.md)
 - [use_throttle_fn](utilities/use_throttle_fn.md)
\ No newline at end of file
diff --git a/docs/book/src/custom.css b/docs/book/src/custom.css
index 78faaf9..e3844ec 100644
--- a/docs/book/src/custom.css
+++ b/docs/book/src/custom.css
@@ -20,4 +20,17 @@
 pre > code {
     border-radius: 5px;
     padding: 1.5rem;
-}
\ No newline at end of file
+}
+
+.meta-data {
+    font-size: 87.5%;
+    display: grid;
+    grid-template-columns: 70px auto;
+    gap: 2rem;
+    align-items: flex-start;
+    margin: 2rem  0 4rem;
+}
+
+.meta-data > div:first-child {
+    opacity: 0.5;
+}
diff --git a/docs/book/src/extract_doc_comment.py b/docs/book/src/extract_doc_comment.py
index 436fb18..7215c4d 100644
--- a/docs/book/src/extract_doc_comment.py
+++ b/docs/book/src/extract_doc_comment.py
@@ -1,8 +1,18 @@
 import sys
 import re
+import os
 
 
 def main():
+    category = os.path.split(os.getcwd())[-1]
+
+    print(f"""
+<div class="meta-data">
+    <div>Category</div>
+    <div>{category.title()}</div>
+</div>
+""")
+
     name = sys.argv[1]
     file_name = f"../../../../src/{name}.rs"
 
@@ -49,8 +59,11 @@ def add_source_paragraph(name):
     demo_url = f"https://github.com/Synphonyte/leptos-use/tree/main/examples/{name}"
     docs_url = f"https://docs.rs/leptos-use/latest/leptos_use/fn.{name}.html"
 
+    demo_link = " • <a href=\"{demo_url}\" target=\"_blank\">Demo</a>" if os.path.isdir(
+        os.path.join("..", "..", "..", "..", "examples", name)) else ""
+
     print(
-        f"<a href=\"{source_url}\" target=\"_blank\">Source</a> • <a href=\"{demo_url}\" target=\"_blank\">Demo</a> • <a href=\"{docs_url}\" target=\"_blank\">Docs</a>")
+        f"<a href=\"{source_url}\" target=\"_blank\">Source</a>{demo_link} • <a href=\"{docs_url}\" target=\"_blank\">Docs</a>")
 
 
 interal_doc_link_pattern = re.compile(r"\[`([^]]+)\`](?!\()")
diff --git a/docs/book/src/utilities/use_supported.md b/docs/book/src/utilities/use_supported.md
new file mode 100644
index 0000000..581e8bd
--- /dev/null
+++ b/docs/book/src/utilities/use_supported.md
@@ -0,0 +1,3 @@
+# use_supported
+
+<!-- cmdrun python3 ../extract_doc_comment.py use_supported -->
diff --git a/docs/book/src/watch/watch.md b/docs/book/src/watch/watch.md
new file mode 100644
index 0000000..6087512
--- /dev/null
+++ b/docs/book/src/watch/watch.md
@@ -0,0 +1,3 @@
+# watch
+
+<!-- cmdrun python3 ../extract_doc_comment.py watch -->
diff --git a/src/lib.rs b/src/lib.rs
index a9a3552..3d44d29 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,18 +1,25 @@
 //! Collection of essential Leptos utilities inspired by SolidJS USE / VueUse
 
 pub mod core;
-mod use_debounce_fn;
-mod use_event_listener;
-mod use_scroll;
-mod use_throttle_fn;
-pub mod utils;
-
 #[cfg(feature = "docs")]
 pub mod docs;
+mod use_debounce_fn;
+mod use_event_listener;
+#[cfg(web_sys_unstable_apis)]
+mod use_resize_observer;
+mod use_scroll;
+mod use_supported;
+mod use_throttle_fn;
+pub mod utils;
+mod watch;
 
 pub use use_debounce_fn::*;
 pub use use_event_listener::*;
+#[cfg(web_sys_unstable_apis)]
+pub use use_resize_observer::*;
 pub use use_scroll::*;
+pub use use_supported::*;
 pub use use_throttle_fn::*;
+pub use watch::*;
 
 extern crate self as leptos_use;
diff --git a/src/use_debounce_fn.rs b/src/use_debounce_fn.rs
index dece312..ed1184a 100644
--- a/src/use_debounce_fn.rs
+++ b/src/use_debounce_fn.rs
@@ -64,7 +64,7 @@ use leptos::MaybeSignal;
 /// ## Recommended Reading
 ///
 /// - [**Debounce vs Throttle**: Definitive Visual Guide](https://redd.one/blog/debounce-vs-throttle)
-pub fn use_debounce_fn<F>(func: F, ms: impl Into<MaybeSignal<f64>>) -> impl Fn()
+pub fn use_debounce_fn<F>(func: F, ms: impl Into<MaybeSignal<f64>>) -> impl Fn() + Clone
 where
     F: FnOnce() + Clone + 'static,
 {
@@ -76,7 +76,7 @@ pub fn use_debounce_fn_with_options<F>(
     func: F,
     ms: impl Into<MaybeSignal<f64>>,
     options: DebounceOptions,
-) -> impl Fn()
+) -> impl Fn() + Clone
 where
     F: FnOnce() + Clone + 'static,
 {
diff --git a/src/use_resize_observer.rs b/src/use_resize_observer.rs
new file mode 100644
index 0000000..8c980c7
--- /dev/null
+++ b/src/use_resize_observer.rs
@@ -0,0 +1,59 @@
+use crate::core::ElementMaybeSignal;
+use crate::use_supported;
+use default_struct_builder::DefaultBuilder;
+use leptos::*;
+use std::cell::RefCell;
+use std::rc::Rc;
+use wasm_bindgen::{JsCast, JsValue};
+
+pub fn use_resize_observer_with_options<El, T, F>(
+    cx: Scope,
+    target: El, // TODO : multiple elements?
+    callback: F,
+    options: web_sys::ResizeObserverOptions,
+) where
+    (Scope, El): Into<ElementMaybeSignal<T, web_sys::Element>>,
+    T: Into<web_sys::Element> + Clone + 'static,
+    F: FnMut(Vec<web_sys::ResizeObserverEntry>, web_sys::ResizeObserver) + 'static,
+{
+    let observer: Rc<RefCell<Option<web_sys::ResizeObserver>>> = Rc::new(RefCell::new(None));
+
+    let is_supported = use_supported(cx, || JsValue::from("ResizeObserver").js_in(&window()));
+
+    let obs = Rc::clone(&observer);
+    let cleanup = move || {
+        let observer = obs.borrow_mut();
+        if let Some(o) = *observer {
+            o.disconnect();
+            *observer = None;
+        }
+    };
+
+    let target = target.into();
+
+    let clean = cleanup.clone();
+    create_effect(cx, move |_| {
+        clean();
+
+        if is_supported() {
+            let obs = web_sys::ResizeObserver::new(move |entries: &js_sys::Array, observer| {
+                callback(
+                    entries
+                        .to_vec()
+                        .into_iter()
+                        .map(|v| v.unchecked_into::<web_sys::ResizeObserver>(&options)),
+                    observer,
+                );
+            })
+            .expect("failed to create ResizeObserver");
+
+            observer.observe(&target.get());
+
+            observer.replace(obs);
+        }
+    });
+
+    let stop = move || {
+        cleanup();
+    };
+}
diff --git a/src/use_supported.rs b/src/use_supported.rs
new file mode 100644
index 0000000..f8dc29c
--- /dev/null
+++ b/src/use_supported.rs
@@ -0,0 +1,26 @@
+use leptos::*;
+
+/// SSR compatibe `is_supported`
+///
+/// ## Usage
+///
+/// ```
+/// # use leptos::*;
+/// # use leptos_use::use_supported;
+/// # use wasm_bindgen::JsValue;
+/// #
+/// # pub fn Demo(cx: Scope) -> impl IntoView {
+/// let is_supported = use_supported(
+///     cx,
+///     || JsValue::from("getBattery").js_in(&window().navigator())
+/// );
+///
+/// if is_supported() {
+///     // do something
+/// }
+/// #    view! { cx, }
+/// # }
+/// ```
+pub fn use_supported(cx: Scope, callback: impl Fn() -> bool + 'static) -> Signal<bool> {
+    Signal::derive(cx, callback)
+}
diff --git a/src/watch.rs b/src/watch.rs
new file mode 100644
index 0000000..30a4c24
--- /dev/null
+++ b/src/watch.rs
@@ -0,0 +1,84 @@
+use leptos::*;
+use std::cell::RefCell;
+
+/// A version of `create_effect` that listens to any dependency that is accessed inside `deps`.
+/// Also a stop handler is returned.
+/// If `immediate` is false, the `callback` will not run immediately but only after
+/// the first change is detected of any signal that is accessed in `deps`.
+/// The return value of `deps` is passed into `callback` as an argument together with the previous value
+/// and the previous value that the `callback` itself returned last time.
+///
+/// # Usage
+///
+/// ```
+/// # use std::time::Duration;
+/// # use leptos::*;
+/// # use leptos_use::watch;
+/// #
+/// # pub fn Demo(cx: Scope) -> impl IntoView {
+/// let (num, set_num) = create_signal(cx, 0);
+///
+/// let stop = watch(
+///     cx,
+///     num,
+///     move |num, _, _| {
+///         log!("number {}", num);
+///     },
+///     true,
+/// );
+///
+/// set_num(1); // > "number 1"
+///
+/// set_timeout_with_handle(move || {
+///     stop(); // stop watching
+///
+///     set_num(2); // nothing happens
+/// }, Duration::from_millis(1000));
+/// #    view! { cx, }
+/// # }
+/// ```
+pub fn watch<W, T, DFn, CFn>(
+    cx: Scope,
+    deps: DFn,
+    callback: CFn,
+    immediate: bool,
+) -> impl Fn() + Clone
+where
+    DFn: Fn() -> W + 'static,
+    CFn: Fn(&W, Option<&W>, Option<T>) -> T + 'static,
+    W: 'static,
+    T: 'static,
+{
+    let (is_active, set_active) = create_signal(cx, true);
+
+    let prev_deps_value: RefCell<Option<W>> = RefCell::new(None);
+    let prev_callback_value: RefCell<Option<T>> = RefCell::new(None);
+
+    create_effect(cx, move |did_run_before| {
+        if !is_active() {
+            return ();
+        }
+
+        let deps_value = deps();
+
+        if !immediate && did_run_before.is_none() {
+            prev_deps_value.replace(Some(deps_value));
+            return ();
+        }
+
+        let callback_value = callback(
+            &deps_value,
+            prev_deps_value.borrow().as_ref(),
+            prev_callback_value.take(),
+        );
+        prev_callback_value.replace(Some(callback_value));
+
+        prev_deps_value.replace(Some(deps_value));
+
+        ()
+    });
+
+    move || {
+        set_active(false);
+    }
+}