Dien,

Interesting topic, subject, Ideas as usual...

Googling around, Lots of different options, ideas, resources and business models in those Specialized Niches of Handwriting on the Web!...

Related to Handwriting type things, Apps, developments throughout Web communications and much, much more...

Instead of just links, if you Absolutely Love Handwriting type ideas...

Give it a Twist into...

Simply start-up A Service related Concept with Web Specialization along with a different mix of Uniqueness...
https://www.google.com/search?q=hand...24FIWKrAG17IFw

What Does Your Handwriting Say About You? ...
http://visual.ly/what-does-your-hand...-say-about-you

All the best,
Phil