diff --git a/include/ker/string.hpp b/include/ker/string.hpp
index 5f775de..2edac22 100644
--- a/include/ker/string.hpp
+++ b/include/ker/string.hpp
@@ -1,10 +1,45 @@
 #pragma once
 
-#include <stdlib.h>
 #include <inttypes.h>
-#if !defined(CIRCUIT_OS)
-    #include <stdlib.h>
-    #include <string.h>
+#if defined(CIRCUIT_OS)
+#include <kstdlib.h>
+#error "???"
+#else
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+
+// itoa is not ANSI C
+/**
+ * C++ version 0.4 char* style "itoa":
+ * Written by Lukás Chmela
+ * Released under GPLv3.
+ */
+static inline char* itoa(int value, char* result, int base) {
+	// check that the base if valid
+	if (base < 2 || base > 36) { *result = '\0'; return result; }
+
+	char* ptr = result, *ptr1 = result, tmp_char;
+	int tmp_value;
+
+	do {
+		tmp_value = value;
+		value /= base;
+		*ptr++ = "zyxwvutsrqponmlkjihgfedcba9876543210123456789abcdefghijklmnopqrstuvwxyz" [35 + (tmp_value - value * base)];
+	} while ( value );
+
+	// Apply negative sign
+	if (tmp_value < 0) *ptr++ = '-';
+	*ptr-- = '\0';
+	while(ptr1 < ptr) {
+		tmp_char = *ptr;
+		*ptr--= *ptr1;
+		*ptr1++ = tmp_char;
+	}
+	return result;
+}
+
+
 #endif
 
 #define KER_STRING_AVAILABLE
@@ -45,6 +80,12 @@ namespace ker
             this->copyFrom(reinterpret_cast<const uint8_t*>(text), strlen(text));
 		}
 
+		String(const char *bytes, size_t length) :
+			String(reinterpret_cast<const uint8_t *>(bytes), length)
+		{
+
+		}
+
 		String(const uint8_t *bytes, size_t length) :
             mText(nullptr),
 			mLength(length)
@@ -59,6 +100,11 @@ namespace ker
             }
 		}
 
+		uint8_t at(size_t index) const
+		{
+			return this->mText[index];
+		}
+
 		size_t length() const
 		{
 			return this->mLength;
diff --git a/include/ker/vector.hpp b/include/ker/vector.hpp
index 58bb5d2..ce4741a 100644
--- a/include/ker/vector.hpp
+++ b/include/ker/vector.hpp
@@ -2,11 +2,13 @@
 
 #include <inttypes.h>
 #include <stddef.h>
-#include <string.h>
-#include "new.hpp"
 
-#if !defined(CIRCUIT_OS)
+#if defined(CIRCUIT_OS)
+#include "kstdlib.h"
+#include "new.hpp"
+#else
 #include <stdlib.h>
+#include <string.h>
 #include <new>
 #endif
 
@@ -119,11 +121,9 @@ namespace ker
         }
 
         T& insert(size_t index, const T& value)
-        {
-            if(this->mReserved < (this->mLength + 1)) {
-                this->resize(this->mLength + 1);
-            }
-            for(int32_t i = this->mLength - 1; i > static_cast<int32_t>(index); i--) {
+		{
+			this->resize(this->mLength + 1);
+			for(int32_t i = this->mLength - 2; i >= static_cast<int32_t>(index); i--) {
                 // Move every item backwards
                 this->mData[i+1] = this->mData[i];
             }
@@ -150,7 +150,7 @@ namespace ker
 
 			if(current > size) {
 				// "Downgrade"
-				for(size_t i = this->mLength - 1; i > size; i--) {
+				for(int32_t i = static_cast<int32_t>(this->mLength) - 1; i > static_cast<int32_t>(size); i--) {
 					this->mData[i].~T();
 				}
 			} else {
@@ -196,6 +196,14 @@ namespace ker
             return this->mData[this->mLength - 1];
         }
 
+		T &front() {
+			return this->mData[0];
+		}
+
+		T &back() {
+			return this->mData[this->mLength - 1];
+		}
+
 		T* begin()
 		{
 			return &this->mData[0];
diff --git a/include/stdlib.h b/include/kstdlib.h
similarity index 100%
rename from include/stdlib.h
rename to include/kstdlib.h
diff --git a/include/kstring.h b/include/kstring.h
new file mode 100644
index 0000000..f949f0b
--- /dev/null
+++ b/include/kstring.h
@@ -0,0 +1,3 @@
+#pragma once
+
+#include "kstdlib.h"
diff --git a/include/string.h b/include/string.h
deleted file mode 100644
index 08e1311..0000000
--- a/include/string.h
+++ /dev/null
@@ -1,3 +0,0 @@
-#pragma once
-
-#include "stdlib.h"