Simple FM Go -to- Paypal strategy?

I have created a nifty little FM Go solution for quizzing myself on backgammon problems that I think others in the backgammon community might find very useful.  Since I don't really anticipate it being a big money-maker, it's not worth it to me to try to do an elaborate purchase/licensing/subscription/encryption process for "selling" the solution to players.  What I'd like to do instead is just make it available for people to download onto their iPads and use for free, and include a sort of "tip jar" request that if they found the solution useful, they could go to PayPal and make a $10 or $25 or whatever they feel it was worth to me.  If it were to bring in say $1000 it would be worthwhile for me to produce further quizzes.

So, what would be the simplest way for me to set up that sort of 'tip jar'?   I could just have a screen where I provide my email and suggest they go to PayPal themselves - - - but is there a way I could have them click a button that would say open their web browser and take them to PayPal?  Or is there a reasonably simple way way to put a PayPal logo button on a Filemaker layout and set it up to fill in my email address automatically for a Donation?