It looks like a great idea. The design seems good in general. I would suggest trying to find specific areas where you can be the best on the web, which will unfortunately require that you seek traffic in a specialized way also.
My first thoughts for additional features were specific calendar conversions (Jewish, Chinese, etc) and Unicode characters. These are major areas and are done well elsewhere. Perhaps you could partner with some specific sites.
I noticed a problem with the age calculator. 22 March 2014 gave age 0, as it should, but 21 March 2014 gave age 1. The change from zero to 1 should have occured on 21 Feb, so I think the month logic is off by 1.
I wish you the best with the site. With search engines and Wolfram (among others) now trying to be universal converters, it will definitely take some effort to find your niche, but I believe you can do well with research and creativity.
@SonLight Thanks for your support!
I have fixed the age calculator.
Good website, for sure it will work and generate traffic
It seems it's a good site!
I like the QR code generator, and I think the conversions will be useful, especially the PayPal fee calculator.
I also like how the mobile edition is almost exactly the same - some websites think it's best to reduce its content for a mobile, but you haven't made that mistake, so well done!
Keep up the good work!
- Sorcerertech :)
It's a very useful website!
Bookmarked it instantly.
It seems very useful, and I'm going to share it, but I am curious about something, because I started a blog and I'm going to start building websites. I was wondering if you can find your site when you go to google and search for the tools? If not, how do you plan to increase traffic?