As our reviewer Lalitha Nataraj notes, today's apps were created using OCG Studio's "Develop-Your-Own" framework, designed by the developer for artists and illustrators who want to build their own interactive productions. On their website the developer comments, "Writers/illustrators can prepare a lot of the artwork, music, sounds and interactivity themselves. We can build the app around this already prepared content, saving both time and money. A high-quality app, but not the price." For more on the making of the "Mortimer" apps, OCG Studios offers a look at their process. Utilizing the OCG Studio “Develop-Your-Own” (DYO) framework, the "Artist Mortimer" apps by Bo Zaunders, The Artist Who Stole Bits of the World (2012) and The Artist Who Saved Bits of the World (2016; iOS, Free; Android, Free; Gr 1–3), are engaging tales enhanced by vivid artwork, music, and interactivity. In the earlier app, Mortimer is an artist who loves to paint, but unfortunately his true-to-life subjects disappear from the real world, forever memorialized on his canvas. Naturally, this profoundly affects those around Mortimer, because after all, no one wants to see oceans or sunsets disappear forever. The artist tries to resolve the issue by painting away problems such as a runaway rhinoceros, a forest fire, and even a little boy’s nightmare. However, this pat ending confuses rather than mollifies readers, which is why the later version of this app attempts to focus Mortimer’s efforts on addressing climate change and other environmental concerns. In The Artist Who Saved Bits of the World (iOS, $.99; Android, $.99; Gr 1–3), Mortimer continues to steal bits of the real world for his canvases until he discovers that the situation can be reversed; he can paint a better and brighter world. Soon, the artist finds himself addressing global warming by eliminating a smoke factory and replacing it with solar panels and wind generators, replenishing ice floes for stranded polar bears, and more. Far from heavy-handed, Mortimer’s charming and kindhearted approach to solving environmental dilemmas is timely and will resonate with young readers. Both apps are illustrated by Zaunders, whose whimsical artwork features line drawings and pastel tones. Slight animations appear throughout the stories and more occur when viewers tap the screen (a polar bear waves, a figure walks, etc.) The apps contain three modes of storytelling: “Read Myself,” “Read to Me,” and “Autoplay.” In the “Read to Me” and “Autoplay” modes, text is highlighted to match Zaunders's cadence; unfortunately "Autoplay" moves a little too quickly for youngsters to activate animations and sounds (a hissing snake, barking dog, etc.). In the “Read Myself” mode, users have the option of recording their narration. VERDICT Both stories are enjoyable, but Mortimer 2 with its added content and focused narrative is the one the kids will revisit.—Lalitha Nataraj, Escondido Public Library, Escondido, CA

The Artist Mortimer 2 (OCG Studios, Zaunders) provides residents with bicycles when traffic gets heavy