As a part of testing you should start looking into the NFRs testing like Performance, Load, Security, UX etc. testing. Study about the FRUPS+ . Performance testing too is equally important as other functional testing, as I have seen many projects to get failed/escalated to higher levels which failed to deliver good performance and Performance testing indeed is a very vast topic to be covered especially about:-
- What is it and its impact?
- How to measure performance?
- Different tools available in market
- Performance planning and execution
- Report analysis
- System monitoring etc.
Now, a days many performance testing tools provide integration with functional testing tools (like JMeter with Selenium, HTTPWatch with WatiR/WatiN etc.). Performance in mobile applications is a big challenge as there you have very limited resources and mobile applications are more in trend now.
Then, you can also start with the security testing/OWASP. This again includes mobile applications. Another area to be looked upon is Database testing; this too is a good, technically sound, interesting and required feature for testers.
These are from testing point of view and require Dynamic + Static testing involvement and will increase your technical knowledge too about the applications under consideration.
Running a new tool may not be a big deal for you if you have good command on one tool as your concepts are clear and you yourself have worked good in one tool, definitely you can explore more tools for adding up to your knowledge.
Go for some kind of certification (if you not already have) this will add value to you resume and skillset too. But not having certification doesn't mean that you don't have knowledge.
From QA point of view there is a lot to be covered and you can start with that too, like:
- Participation in requirement analysis and review
- Manual and Automated test cases review for other team members
- Involve yourself in Client meetings/calls (if not directly then indirectly i.e. sit in call as a passive user but make notes and analyze the client requirements)
- If there are more QAs in your team, ask to start mentoring a fresher/junior (I assure you will learn a lot from this mentoring, but only if your manager permits so, as it depends from Organization to Organization)
- Involvement in Static testing/Reviews/Demo etc.
There is much more in this line but to start with these are good options. Responsibilities of your QA line may also depend upon your team and Organization, but if you develop capability and show learning skills you should definitely get opportunity to implement them.