diff --git a/index.html b/index.html
index 9dfeb2b..8d1e8f1 100644
--- a/index.html
+++ b/index.html
@@ -335,8 +335,6 @@
               { kind: 'block', type: 'wc' },
               { kind: 'block', type: 'sort' },
               { kind: 'block', type: 'uniq' },
-              { kind: 'block', type: 'findDuplicates' },
-              { kind: 'block', type: 'showUniqs' },
               { kind: 'block', type: 'cut' },
               { kind: 'block', type: 'sed' }
             ]
diff --git a/public/blocks/findDuplicatesBlock.js b/public/blocks/findDuplicatesBlock.js
deleted file mode 100644
index 371d038..0000000
--- a/public/blocks/findDuplicatesBlock.js
+++ /dev/null
@@ -1,18 +0,0 @@
-var findDuplicatesBlock = {
-  type: 'findDuplicates',
-  message0: '%{BKY_FIND_DUPLICATES}',
-  category: 'Text Processing',
-  unix_description: [
-    {
-      duplicates: '-d' // uniq -d
-    }
-  ],
-
-  style: 'Text Processing',
-  previousStatement: 'Action',
-  nextStatement: 'Action',
-  tooltip: '%{BKY_FIND_DUPLICATES_TOOLTIP}',
-  helpUrl: '' // URL to further information or documentation.
-};
-
-Blockly.defineBlocksWithJsonArray([findDuplicatesBlock]);
diff --git a/public/blocks/showUniqsBlock.js b/public/blocks/showUniqsBlock.js
deleted file mode 100644
index 538c209..0000000
--- a/public/blocks/showUniqsBlock.js
+++ /dev/null
@@ -1,18 +0,0 @@
-var showUniqsBlock = {
-  type: 'showUniqs',
-  message0: '%{BKY_SHOWUNIQS}',
-  category: 'Text Processing',
-  unix_description: [
-    {
-      uniq: '-u' // uniq -u
-    }
-  ],
-
-  style: 'Text Processing',
-  previousStatement: 'Action',
-  nextStatement: 'Action',
-  tooltip: '%{BKY_SHOWUNIQS_TOOLTIP}',
-  helpUrl: '%{BKY_SHOWUNIQS_HELPURL}' // URL to further information or documentation.
-};
-
-Blockly.defineBlocksWithJsonArray([showUniqsBlock]);
diff --git a/public/blocks/sortBlock.js b/public/blocks/sortBlock.js
index 2ddffeb..5612a45 100644
--- a/public/blocks/sortBlock.js
+++ b/public/blocks/sortBlock.js
@@ -7,7 +7,7 @@ var sortBlock = {
       desc: '-r',
       numeric_sorting: '-n',
       sort_delimiter: "-t'str'",
-      sort_column: '-k',
+      sort_column: '-k ',
       uniq_elements: '-u',
       ignore_nonPrintable: '-i',
       ignore_leading_blanks: '-b'
diff --git a/public/blocks/uniqBlock.js b/public/blocks/uniqBlock.js
index 8abc0af..b696971 100644
--- a/public/blocks/uniqBlock.js
+++ b/public/blocks/uniqBlock.js
@@ -6,7 +6,10 @@ var uniqBlock = {
     {
       none: '',
       occurencies: '-c',
-      caseInsensitive: '-i'
+      caseInsensitive: '-i',
+      outputNonRepeatedLines: '-u',
+      outputSingleCopyOfRepeatedLines: '-d',
+      skipChars: '-s str'
     }
   ],
 
@@ -26,7 +29,30 @@ var uniqBlock = {
       checked: false // by default it's disabled
     }
   ],
-
+  message3: '%{BKY_UNIQ_OUTPUT_NON_REPEATED_LINES}',
+  args3: [
+    {
+      type: 'field_checkbox',
+      name: 'outputNonRepeatedLines',
+      checked: false // by default it's disabled
+    }
+  ],
+  message4: '%{BKY_UNIQ_OUTPUT_SINGLE_COPY_OF_REPEATED_LINES}',
+  args4: [
+    {
+      type: 'field_checkbox',
+      name: 'outputSingleCopyOfRepeatedLines',
+      checked: false // by default it's disabled
+    }
+  ],
+  message5: '%{BKY_UNIQ_SKIP_CHARS}',
+  args5: [
+    {
+      type: 'field_input',
+      name: 'skipChars',
+      text: ''
+    }
+  ],
   style: 'Text Processing',
   previousStatement: 'Action',
   nextStatement: 'Action',
diff --git a/public/img/blockly_photo.png b/public/img/blockly_photo.png
index ff2618c..e8c216c 100644
Binary files a/public/img/blockly_photo.png and b/public/img/blockly_photo.png differ
diff --git a/public/img/combine_files.png b/public/img/combine_files.png
index 4b06dee..8bf47b1 100644
Binary files a/public/img/combine_files.png and b/public/img/combine_files.png differ
diff --git a/public/img/convert_domains.png b/public/img/convert_domains.png
index 1594e5f..4c013d7 100644
Binary files a/public/img/convert_domains.png and b/public/img/convert_domains.png differ
diff --git a/public/img/extract_columns.png b/public/img/extract_columns.png
index d42f549..4f11600 100644
Binary files a/public/img/extract_columns.png and b/public/img/extract_columns.png differ
diff --git a/public/img/filter_rows_and_count_lines.png b/public/img/filter_rows_and_count_lines.png
index 887f0e3..d3da367 100644
Binary files a/public/img/filter_rows_and_count_lines.png and b/public/img/filter_rows_and_count_lines.png differ
diff --git a/public/img/remove_duplicate_lines_and_sort.png b/public/img/remove_duplicate_lines_and_sort.png
index 0b00ff1..41f7fa4 100644
Binary files a/public/img/remove_duplicate_lines_and_sort.png and b/public/img/remove_duplicate_lines_and_sort.png differ
diff --git a/public/js/el.js b/public/js/el.js
index e718596..ed04433 100644
--- a/public/js/el.js
+++ b/public/js/el.js
@@ -49,8 +49,8 @@ Blockly.Msg['CONDITION_OUTPUT_HELPURL'] = 'https://www.google.com/';
 Blockly.Msg['CUT'] = 'Αποκοπή σε αρχείο ή συμβολοσειρά';
 Blockly.Msg['CUT_DELIMITER'] = 'Διαχωριστικό';
 Blockly.Msg['CUT_DEFINE_COLUMNS'] = 'Ορισμός στηλών';
-Blockly.Msg['CUT_START'] = 'Έναρξη υποσυμβολοσειράς';
-Blockly.Msg['CUT_END'] = 'Τέλος';
+Blockly.Msg['CUT_START'] = 'Έναρξη υποσυμβολοσειράς : ';
+Blockly.Msg['CUT_END'] = 'Τέλος : ';
 Blockly.Msg['CUT_TOOLTIP'] =
   'Αποκοπή σε ένα αρχείο ή μια συμβολοσειρά.\nΓια συνεχόμενες αποκοπές χρησιμοποιήστε κόμμα(,) , για αποκοπές εύρους χρησιμοποιήστε παύλα (-)';
 Blockly.Msg['CUT_HELPURL'] = 'https://www.google.com/';
@@ -127,7 +127,7 @@ Blockly.Msg['LS_MESSAGE'] = 'Λίστα αρχείων & καταλόγων';
 Blockly.Msg['LS_SHOW_DETAILS'] = 'Εμφάνιση λεπτομερειών %1';
 Blockly.Msg['LS_SUBDIRECTORIES'] = 'Αναζήτηση σε όλους τους υποκαταλόγους %1';
 Blockly.Msg['LS_HIDDEN'] = 'Εμφάνιση κρυφών αρχείων %1';
-Blockly.Msg['LS_REVERSE_ORDER'] = '%1 Εμφάνιση σε αντίστροφη σειρά';
+Blockly.Msg['LS_REVERSE_ORDER'] = 'Εμφάνιση σε αντίστροφη σειρά %1';
 Blockly.Msg['LS_TOOLTIP'] = 'Λίστα περιεχομένων καταλόγου';
 Blockly.Msg['LS_HELPURL'] = 'https://www.google.com/';
 Blockly.Msg['LN_MESSAGE'] = 'Σύνδεση αρχείων';
@@ -921,6 +921,12 @@ Blockly.Msg['UNIQ'] = 'Αφαίρεση διπλότυπων γραμμών στ
 Blockly.Msg['UNIQ_COUNT'] =
   'Μέτρηση των εμφανίσεων των \n γραμμών που αφαιρέθηκαν %1';
 Blockly.Msg['UNIQ_CASE'] = ' Χωρίς διάκριση πεζών-κεφαλαίων %1';
+Blockly.Msg['UNIQ_OUTPUT_NON_REPEATED_LINES'] =
+  'Εμφάνιση μόνο μη επαναλαμβανόμενων γραμμών %1';
+Blockly.Msg['UNIQ_OUTPUT_SINGLE_COPY_OF_REPEATED_LINES'] =
+  'Εμφάνιση μόνο ενός αντίγραφου των επαναλαμβανόμενων γραμμών %1';
+Blockly.Msg['UNIQ_SKIP_CHARS'] =
+  'Παράλειψη των πρώτων %1 χαρακτήρων κάθε γραμμής';
 Blockly.Msg['UNIQ_TOOLTIP'] =
   'Αναφορά ή φιλτράρισμα επαναλαμβανόμενων γραμμών σε ένα αρχείο';
 Blockly.Msg['UNIQ_HELPURL'] = 'https://www.google.com/';
diff --git a/public/js/en.js b/public/js/en.js
index 2b4656c..5a07c9a 100644
--- a/public/js/en.js
+++ b/public/js/en.js
@@ -20,7 +20,7 @@ Blockly.Msg['AWK_VARIABLE_INPUT'] = 'Variable input';
 Blockly.Msg['AWK_BEGIN'] = 'Execute once before data is processed';
 Blockly.Msg['AWK_ACTION'] = 'Action';
 Blockly.Msg['AWK_END'] = 'Execute once after data is processed';
-Blockly.Msg['AWK_PRINT'] = 'columns to print';
+Blockly.Msg['AWK_PRINT'] = 'Columns to print';
 Blockly.Msg['AWK_TOOLTIP'] =
   'pattern-directed scanning and processing language';
 Blockly.Msg['AWK_HELPURL'] = 'https://www.google.com/';
@@ -48,8 +48,8 @@ Blockly.Msg['CONDITION_OUTPUT_HELPURL'] = 'https://www.google.com/';
 Blockly.Msg['CUT'] = 'Cut out in file or string';
 Blockly.Msg['CUT_DELIMITER'] = 'Delimiter';
 Blockly.Msg['CUT_DEFINE_COLUMNS'] = 'Define columns';
-Blockly.Msg['CUT_START'] = 'substring start';
-Blockly.Msg['CUT_END'] = 'end';
+Blockly.Msg['CUT_START'] = 'Substring start : ';
+Blockly.Msg['CUT_END'] = 'End : ';
 Blockly.Msg['CUT_TOOLTIP'] =
   'Cut out in a file or a string.\nFor consecutive cuts use comma(,) , for range cuts use hyphen (-)';
 Blockly.Msg['CUT_HELPURL'] = 'https://www.google.com/';
@@ -124,7 +124,7 @@ Blockly.Msg['LS_MESSAGE'] = 'List files & directories';
 Blockly.Msg['LS_SHOW_DETAILS'] = 'Show details %1';
 Blockly.Msg['LS_SUBDIRECTORIES'] = 'Search in all subdirectories %1';
 Blockly.Msg['LS_HIDDEN'] = 'Show hidden files %1';
-Blockly.Msg['LS_REVERSE_ORDER'] = '%1 Show in reverse order';
+Blockly.Msg['LS_REVERSE_ORDER'] = 'Show in reverse order %1';
 Blockly.Msg['LS_TOOLTIP'] = 'List directory contents';
 Blockly.Msg['LS_HELPURL'] = 'https://www.google.com/';
 Blockly.Msg['LN_MESSAGE'] = 'Link files';
@@ -892,6 +892,11 @@ Blockly.Msg['UNIQ'] = 'Remove duplicate lines in file\n';
 Blockly.Msg['UNIQ_COUNT'] =
   'Count the occurencies of \n duplicates lines removed %1';
 Blockly.Msg['UNIQ_CASE'] = 'Case sensitive %1';
+Blockly.Msg['UNIQ_OUTPUT_NON_REPEATED_LINES'] =
+  'Output only non-repeated lines %1';
+Blockly.Msg['UNIQ_OUTPUT_SINGLE_COPY_OF_REPEATED_LINES'] =
+  'Output only one copy of repeated lines %1';
+Blockly.Msg['UNIQ_SKIP_CHARS'] = 'Skip first %1 characters of each line';
 Blockly.Msg['UNIQ_TOOLTIP'] = 'Report or filter out repeated lines in a file';
 Blockly.Msg['UNIQ_HELPURL'] = 'https://www.google.com/';
 
diff --git a/public/main.js b/public/main.js
index 11adb03..132b731 100644
--- a/public/main.js
+++ b/public/main.js
@@ -565,7 +565,11 @@ document
     generatedCommand = replaceKeywords(generatedCommand);
 
     // Combine the constructed UNIX command and filename
-    document.getElementById('resultsText').innerText = generatedCommand;
+    if (generatedCommand.length > 0) {
+      document.getElementById('resultsText').innerText = generatedCommand;
+    } else {
+      document.getElementById('resultsText').innerText = '\n'; // Insert a newline character if the command is empty so that the results area does not shrink
+    }
 
     console.log('Generated command:', generatedCommand);
     if (blockCount > 0) {
diff --git a/views/register.ejs b/views/register.ejs
index 7dc7183..00622ac 100644
--- a/views/register.ejs
+++ b/views/register.ejs
@@ -98,11 +98,6 @@
                 </div>
                 <input id="password" name="password" placeholder="Password" type="password" required class="validate" autocomplete="on">
             </div>
-        <!-- Checkbox for data usage agreement -->
-        <div class="form-group" style="margin-top: 20px;  text-align: center;">
-            <input type="checkbox" id="dataAgreement" name="dataAgreement" value="agree" required>
-            <label for="dataAgreement" style="font-size: 0.9em; margin-left: 5px;">I agree to allow my data to be used for research purposes</label>
-        </div>
             <input type="submit" value="Register" />
         </form>
         <!-- Divider with text -->
diff --git a/views/tutorials.ejs b/views/tutorials.ejs
index b4a9364..006932d 100644
--- a/views/tutorials.ejs
+++ b/views/tutorials.ejs
@@ -105,7 +105,7 @@
                             <img src="img/blockly_photo.png" alt="Blockly Unix" class="img-fluid" style="width: 700px; height: auto;">
                         </div>
                         <p>
-                            The corresponding Unix command for this task is: <strong>awk -F';' ' $3 == "empt" ' test.txt | sort -r -k2 | uniq -c | head -n 50 > newFile.txt</strong>
+                            The corresponding Unix command for this task is: <strong>awk -F';' ' $3 == "empt" ' test.txt | sort -r -k 2 | uniq -c | head -n 50 > newFile.txt</strong>
                         </p>
                     </div>
             </li>