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..2191e2518
--- /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(StringUtils.GetLength(sampleText));
+print(lengthOfText);
+
+let start = 7;
+let end = 12;
+let substringResult = StringUtils.substring(sampleText, start, end);
+print(substringResult);
+
+let searchStr = "World";
+let result2 = to_string(StringUtils.indexOf(sampleText, searchStr));
+print(result2);
+
+let upperCaseText = "Text in upper case: " + StringUtils.toUpperCase(sampleText);
+print(upperCaseText);
+
+let lowerCaseText = "Text in lower case: " + StringUtils.toLowerCase(sampleText);
+print(lowerCaseText);
diff --git a/applications/system/js_app/js_thread.c b/applications/system/js_app/js_thread.c
index 5ca365404..003d8239b 100644
--- a/applications/system/js_app/js_thread.c
+++ b/applications/system/js_app/js_thread.c
@@ -8,6 +8,7 @@
 #include "js_thread.h"
 #include "js_thread_i.h"
 #include "js_modules.h"
+#include "modules/js_string.h"
 
 #define TAG "JS"
 
@@ -202,6 +203,40 @@ static void js_global_to_string(struct mjs* mjs) {
     mjs_return(mjs, ret);
 }
 
+static void js_parse_int(struct mjs* mjs) {
+    mjs_val_t arg = mjs_arg(mjs, 0);
+    size_t str_len;
+    const char* str = NULL;
+    if(mjs_is_string(arg)) {
+        str = mjs_get_string(mjs, &arg, &str_len);
+    } else {
+        mjs_return(mjs, mjs_mk_number(mjs, 0));
+        return;
+    }
+
+    int num = 0;
+    int 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_global_to_hex_string(struct mjs* mjs) {
     double num = mjs_get_int(mjs, mjs_arg(mjs, 0));
     char tmp_str[] = "-FFFFFFFF";
@@ -237,12 +272,16 @@ static int32_t js_thread(void* arg) {
     struct mjs* mjs = mjs_create(worker);
     worker->modules = js_modules_create(mjs, worker->resolver);
     mjs_val_t global = mjs_get_global(mjs);
+
     mjs_set(mjs, global, "print", ~0, MJS_MK_FN(js_print));
     mjs_set(mjs, global, "delay", ~0, MJS_MK_FN(js_delay));
     mjs_set(mjs, global, "to_string", ~0, MJS_MK_FN(js_global_to_string));
     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, "parseint", ~0, MJS_MK_FN(js_parse_int));
+
+    string_utils_init(mjs);
 
     mjs_val_t console_obj = mjs_mk_object(mjs);
     mjs_set(mjs, console_obj, "log", ~0, MJS_MK_FN(js_console_log));
diff --git a/applications/system/js_app/modules/js_string.h b/applications/system/js_app/modules/js_string.h
new file mode 100644
index 000000000..e7dbf8454
--- /dev/null
+++ b/applications/system/js_app/modules/js_string.h
@@ -0,0 +1,150 @@
+#include "../js_modules.h"
+
+static void js_string_substring(struct mjs* mjs) {
+    mjs_val_t arg0 = mjs_arg(mjs, 0);
+    mjs_val_t arg1 = mjs_arg(mjs, 1);
+    mjs_val_t arg2 = mjs_arg(mjs, 2);
+
+    size_t str_len;
+    const char* str = NULL;
+    if(mjs_is_string(arg0)) {
+        str = mjs_get_string(mjs, &arg0, &str_len);
+    } else {
+        mjs_return(mjs, MJS_UNDEFINED);
+        return;
+    }
+
+    size_t start = mjs_is_number(arg1) ? (size_t)mjs_get_int(mjs, arg1) : (size_t)-1;
+    size_t end = mjs_is_number(arg2) ? (size_t)mjs_get_int(mjs, arg2) : (size_t)str_len;
+
+    if((int)start < 0 || end > str_len || start > end) {
+        mjs_return(mjs, MJS_UNDEFINED);
+        return;
+    }
+
+    mjs_val_t substr_obj = mjs_mk_string(mjs, str + start, end - start, 1);
+    mjs_return(mjs, substr_obj);
+}
+
+static void js_string_get_length(struct mjs* mjs) {
+    mjs_val_t arg0 = mjs_arg(mjs, 0);
+    size_t str_len;
+    if(mjs_is_string(arg0)) {
+        const char* str = mjs_get_string(mjs, &arg0, &str_len);
+        UNUSED(str);
+        mjs_return(mjs, mjs_mk_number(mjs, str_len));
+    } else {
+        mjs_return(mjs, MJS_UNDEFINED);
+    }
+}
+
+static void js_string_slice(struct mjs* mjs) {
+    mjs_val_t arg0 = mjs_arg(mjs, 0);
+    mjs_val_t arg1 = mjs_arg(mjs, 1);
+    mjs_val_t arg2 = mjs_arg(mjs, 2);
+
+    size_t str_len;
+    const char* str = NULL;
+    if(mjs_is_string(arg0)) {
+        str = mjs_get_string(mjs, &arg0, &str_len);
+    } else {
+        mjs_return(mjs, MJS_UNDEFINED);
+        return;
+    }
+
+    int start = mjs_is_number(arg1) ? mjs_get_int(mjs, arg1) : 0;
+    int end = mjs_is_number(arg2) ? mjs_get_int(mjs, arg2) : (int)str_len;
+
+    if(start < 0) start = (int)str_len + start < 0 ? 0 : (int)str_len + start;
+    if(end < 0) end = (int)str_len + end < 0 ? 0 : (int)str_len + end;
+    start = start > (int)str_len ? (int)str_len : start;
+    end = end > (int)str_len ? (int)str_len : end;
+
+    if(end < start) end = start;
+
+    mjs_val_t resultStr = mjs_mk_string(mjs, str + start, end - start, 1);
+    mjs_return(mjs, resultStr);
+}
+
+static void js_string_index_of(struct mjs* mjs) {
+    mjs_val_t arg0 = mjs_arg(mjs, 0);
+    mjs_val_t arg1 = mjs_arg(mjs, 1);
+
+    size_t str_len;
+    const char* str = NULL;
+    if(mjs_is_string(arg0)) {
+        str = mjs_get_string(mjs, &arg0, &str_len);
+    } else {
+        mjs_return(mjs, MJS_UNDEFINED);
+        return;
+    }
+
+    const char* searchValue = NULL;
+    if(mjs_is_string(arg1)) {
+        searchValue = mjs_get_string(mjs, &arg1, NULL);
+    } else {
+        mjs_return(mjs, MJS_UNDEFINED);
+        return;
+    }
+
+    char* found = strstr(str, searchValue);
+    int position = found ? (int)(found - str) : -1;
+
+    mjs_return(mjs, mjs_mk_number(mjs, position));
+}
+
+static void js_string_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);
+    } else {
+        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, str_len, 1);
+    free(upperStr);
+    mjs_return(mjs, resultStr);
+}
+
+static void js_string_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);
+    } else {
+        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, str_len, 1);
+    free(lowerStr);
+    mjs_return(mjs, resultStr);
+}
+
+static void string_utils_init(struct mjs* mjs) {
+    mjs_val_t string_utils_obj = mjs_mk_object(mjs);
+    mjs_set(mjs, string_utils_obj, "substring", ~0, MJS_MK_FN(js_string_substring));
+    mjs_set(mjs, string_utils_obj, "slice", ~0, MJS_MK_FN(js_string_slice));
+    mjs_set(mjs, string_utils_obj, "indexOf", ~0, MJS_MK_FN(js_string_index_of));
+    mjs_set(mjs, string_utils_obj, "toUpperCase", ~0, MJS_MK_FN(js_string_to_upper_case));
+    mjs_set(mjs, string_utils_obj, "toLowerCase", ~0, MJS_MK_FN(js_string_to_lower_case));
+    mjs_set(mjs, string_utils_obj, "GetLength", ~0, MJS_MK_FN(js_string_get_length));
+    mjs_val_t global = mjs_get_global(mjs);
+    mjs_set(mjs, global, "StringUtils", ~0, string_utils_obj);
+}
\ No newline at end of file