I'm re-posting an addition request for jSQL Injection as you invited to (spoiler and bias: I'm the creator of jSQL).
The tool is similar to sqlmap but there are differences about design and features, differences are:
- 23 databases supported by jSQL, 12 by sqlmap,
- Recent graph and nosql databases supported by jSQL like Neo4j,
- User oriented GUI (like Burp, W3af, Wireshark...), no bunches of CLI's switches to remember,
- Therefore opened to beginners too,
- No Python, written in Java like Burp,
- Injection algorithms are different,
- SQL syntax is directly accessible to study and to live modifications, no internal design understanding and programming skill required,
- What's happening under the hood is visible, like SQL queries and HTTP requests,
- Visualization of files, admin pages and shells in tabs,
Users like to use both tools together because the approach is different.