My book Space Apps for Android: Discover the Best Astronomy and Space Apps is now for sale on Gumroad. I opened an online store for my books, courses, and other products and this is the first work I put for sale there.
To celebrate, only for the next couple of days you can get $3 off the list price and buy the book at $4.99 instead of $7.99. Just visit this link https://gum.co/spaceappsforandroid/gumintro or enter the promo code gumintro at checkout.
I hope you'll enjoy the book!