You never cease to amaze me with what you can do with a tablet app.
There are a couple of things that I will point out that could've been done differently or omitted.
Be careful with gradients, the show rarely makes use of them, usually for clouds, hills, ground, and the sky. Objects tend to have a solid shadow. Examples in the comic include the math poster and the pillar on the left (for the math poster, you could add either a parchment paper with a geometric shape(s) that is colored like paper or in hue with the wall, plus exclude the text because the show is detailed, but not too detailed).
The word "Cookies" on the jar could be of a different font that isn't so sharp, or be replaces with just squiggles. Same goes for the "Pleaaase", bright red is hard to look at comfortably.
Speaking of Panel 3, the background could have a potentially comedic effect if the background were replaced with a sparkly, bubbly scene like those seen in anime (here's such an example). Your call though.
Round the sharp edges at the bottom of the cookie jar.
Vision: Classic parental pushover scenario. Kind of rare in this day and time, and so bravo for making one.
Originality: I've seen my fair share of "Hnnnng"-induced-by-cuteness comics, this is slightly similar but nonetheless in the same effect. Cuteness is used for benefit though in this case as opposed to just stringing out "DAWWW's".
Technique: Did I mentioned how amazed I was in the first sentence of this critique? No? Well then; I'm amazed.
Impact: This is a very classic comic with a dose of pony (too much if you're prone to heart-attacks from cuteness).
Lovely comic and again a great comic from an unusual tool.