I have an iPad 3 on iOS 9.3.5. I went to download the Photoshop Sketch app in the app store, but i noticed in the app's description it says "*iPad mini 2, 3, 4; iPad Air; iPad Air 2; iPad Pro only". Does that mean the app works only with those devices or that it won't work on my iPad 3? If not, what does that mean? Thanks.
You can use Sketch on an iPad 3. I can understand completely, however, why you were confused by this: "*iPad mini 2, 3, 4; iPad Air; iPad Air 2; iPad Pro only." It doesn't seem to refer back to anything (at least not that I could see).
I'm thinking that what it was referring to is some of the brushes in Sketch. You very likely won't see some of them (the watercolor, and acrylic brushes) and you won't be able to import .tpl brushes. But you'll definitely be able to use the app.
Let me know if you have any additional questions and I'm sorry about the confusing footnote in the AppStore.