Greeting cards are available in every super market. Buy a bunch of them when you buy your groceries which most people do at least once a week. In many other countries, you have to go to a bookstore to buy them. Americans.. stop being so f*cking lazy. That's why many Americans are fat and obese.. from lack of movement. Everything has to be within arms reach.
If you want to send a hand written personal card, use your pen. As a receiver I will appreciate your effort. I want to see real ink on the paper instead of letting me know that you were too lazy. How long does it take to hand sign each card? Your hand getting tired. Take a break and sign some more later. Sign them whiel watching TV if you think the effort is that laborious. Unless you're a celebrity and sending hundreds of cards.
A lot of products just promote more laziness.
Also which tablet or phone is going to make you able to hand write legibly anyways? They suck bad. If you send me a card with such a signature, I will not appreciate it.