diff --git a/applications/system/js_app/examples/apps/Scripts/stringutils.js b/applications/system/js_app/examples/apps/Scripts/stringutils.js
new file mode 100644
index 000000000..51781328d
--- /dev/null
+++ b/applications/system/js_app/examples/apps/Scripts/stringutils.js
@@ -0,0 +1,19 @@
+let sampleText = "Hello, World!";
+
+let lengthOfText = "Length of text: " + to_string(sampleText.length);
+print(lengthOfText);
+
+let start = 7;
+let end = 12;
+let substringResult = sampleText.slice(start, end);
+print(substringResult);
+
+let searchStr = "World";
+let result2 = to_string(sampleText.indexOf(searchStr));
+print(result2);
+
+let upperCaseText = "Text in upper case: " + to_upper_case(sampleText);
+print(upperCaseText);
+
+let lowerCaseText = "Text in lower case: " + to_lower_case(sampleText);
+print(lowerCaseText);
diff --git a/applications/system/js_app/js_thread.c b/applications/system/js_app/js_thread.c
index 5ca365404..fe0b833a0 100644
--- a/applications/system/js_app/js_thread.c
+++ b/applications/system/js_app/js_thread.c
@@ -210,6 +210,88 @@ static void js_global_to_hex_string(struct mjs* mjs) {
     mjs_return(mjs, ret);
 }
 
+static void js_parse_int(struct mjs* mjs) {
+    mjs_val_t arg = mjs_arg(mjs, 0);
+    if(!mjs_is_string(arg)) {
+        mjs_return(mjs, mjs_mk_number(mjs, 0));
+        return;
+    }
+    size_t str_len = 0;
+    const char* str = mjs_get_string(mjs, &arg, &str_len);
+    if((str_len == 0) || (str == NULL)) {
+        mjs_return(mjs, mjs_mk_number(mjs, 0));
+        return;
+    }
+
+    int32_t num = 0;
+    int32_t sign = 1;
+    size_t i = 0;
+
+    if(str[0] == '-') {
+        sign = -1;
+        i = 1;
+    } else if(str[0] == '+') {
+        i = 1;
+    }
+
+    for(; i < str_len; i++) {
+        if(str[i] >= '0' && str[i] <= '9') {
+            num = num * 10 + (str[i] - '0');
+        } else {
+            break;
+        }
+    }
+    num *= sign;
+
+    mjs_return(mjs, mjs_mk_number(mjs, num));
+}
+
+static void js_to_upper_case(struct mjs* mjs) {
+    mjs_val_t arg0 = mjs_arg(mjs, 0);
+
+    size_t str_len;
+    const char* str = NULL;
+    if(mjs_is_string(arg0)) {
+        str = mjs_get_string(mjs, &arg0, &str_len);
+    }
+    if(!str) {
+        mjs_return(mjs, MJS_UNDEFINED);
+        return;
+    }
+
+    char* upperStr = strdup(str);
+    for(size_t i = 0; i < str_len; i++) {
+        upperStr[i] = toupper(upperStr[i]);
+    }
+
+    mjs_val_t resultStr = mjs_mk_string(mjs, upperStr, ~0, true);
+    free(upperStr);
+    mjs_return(mjs, resultStr);
+}
+
+static void js_to_lower_case(struct mjs* mjs) {
+    mjs_val_t arg0 = mjs_arg(mjs, 0);
+
+    size_t str_len;
+    const char* str = NULL;
+    if(mjs_is_string(arg0)) {
+        str = mjs_get_string(mjs, &arg0, &str_len);
+    }
+    if(!str) {
+        mjs_return(mjs, MJS_UNDEFINED);
+        return;
+    }
+
+    char* lowerStr = strdup(str);
+    for(size_t i = 0; i < str_len; i++) {
+        lowerStr[i] = tolower(lowerStr[i]);
+    }
+
+    mjs_val_t resultStr = mjs_mk_string(mjs, lowerStr, ~0, true);
+    free(lowerStr);
+    mjs_return(mjs, resultStr);
+}
+
 #ifdef JS_DEBUG
 static void js_dump_write_callback(void* ctx, const char* format, ...) {
     File* file = ctx;
@@ -243,6 +325,9 @@ static int32_t js_thread(void* arg) {
     mjs_set(mjs, global, "to_hex_string", ~0, MJS_MK_FN(js_global_to_hex_string));
     mjs_set(mjs, global, "ffi_address", ~0, MJS_MK_FN(js_ffi_address));
     mjs_set(mjs, global, "require", ~0, MJS_MK_FN(js_require));
+    mjs_set(mjs, global, "parse_int", ~0, MJS_MK_FN(js_parse_int));
+    mjs_set(mjs, global, "to_upper_case", ~0, MJS_MK_FN(js_to_upper_case));
+    mjs_set(mjs, global, "to_lower_case", ~0, MJS_MK_FN(js_to_lower_case));
 
     mjs_val_t console_obj = mjs_mk_object(mjs);
     mjs_set(mjs, console_obj, "log", ~0, MJS_MK_FN(js_console_log));