adding some more descriptive app titles

app/src/main/res/values-zh-rTW/strings.xml

@@ -11,6 +11,8 @@
     <string name="faq_1_text">點一次會刪除一個字元。長按會馬上重置全部欄位。</string>
 
     <!-- Strings displayed only on Google Playstore. Optional, but good to have -->
+    <!-- App title has to have less than 50 characters. If you cannot squeeze it, just remove a part of it -->
+    <string name="app_title">Simple Calculator - Do your calculations quickly</string>
     <!-- Short description has to have less than 80 chars -->
     <string name="app_short_description">A calculator for your quick calculations.</string>
     <string name="app_long_description">