Web Based Tools

Workbench 
 The one and only tool that everyone should know. If you don't know it, start learning it. It is just the baseline of everything. 
 https://workbench.developerforce.com/login.php?startUrl=%2Fquery.php 
 CloudToolKit 
 Is actually 8 tools - Best practices analyzer, Org Compare tool, Data Compare tool, Schema Lister, Field Creator and validation/trigger switcher 
 https://cloudtoolkit.co/ 
 Profile Power Tools - Mass edit profiles 
 Literally does what it tells you. Allows you to mass edit profiles. 
 https://profilepowertools.com 
 Google for salesforce - Search the web and only get Salesforce related results 
 Avoids you having to applya gazillion filters when doing your Google searches. 
  https://sfdcsearch.com/ 
 Json 2 apex - Create Apex based on your jason 
 http://json2apex.herokuapp.com/ 
 Cert Score Calculator  
 https://scuvanov.github.io/SalesforceCertScoreCalculator/ 
 Permissions Comparison 
 https://perm-comparator.herokuapp.com/ 
 Event Log Viewer 
 https://salesforce-elf.herokuapp.com/ 
 DbDiagram 
 https://dbdiagram.io 
 If you use Lucidchart to genarate your Entity Diagrams you should switch over to this. When you're done with LucidChart, what you have is an image.That work is lost. If you use DbDiagram or equivalent, you just write JSON, which you then can reuse to actually create your fields etc. 
 QueryBuilder 
 https://querybuilder9000.herokuapp.com/ 
 Doing SOQL queries that can be comre complex than reports, but without the hassle, since... a few years now ? no idea.