GoodNotes 5 works on all iOS devices that run iOS 12 or higher.
iOS 12 compatible devices, as stated on Apple's website:
However, it could happen that your iPad model can install GoodNotes 5 but does not support the Apple Pencil.
Apple Pencil 1st generation works with the following iPads:
- iPad Air 3 (2019)
- iPad Mini 5 (2019)
- iPad 10.2in (2019)
- iPad 9.7in (aka iPad 6th gen, 2018)
- iPad Pro 12.9in (2nd gen, 2017)
- iPad Pro 12.9in (1st gen, 2015)
- iPad Pro 10.5in (2017)
- iPad Pro 9.7in (2016)
Apple Pencil 2 works with the following iPads:
- iPad Pro 12.9in (4th gen, 2020)
- iPad Pro 11in (2nd gen, 2020)
- iPad Pro 12.9in (3rd gen, 2018)
- iPad Pro 11in (1st gen, 2018)
The following models can't use the Apple Pencil (first or second generation):
- iPad 9.7in (aka iPad 5th gen, 2017)
- iPad Mini 4 (2015)
- iPad Mini 3 (2014)
- iPad Mini 2 (2013)
- iPad Mini 1 (2012) *
- iPad Air 2 (2014)
- iPad Air 1 (2013)
- iPad 4 (November 2012) *
- iPad 3 (March 2012) *
- iPad 2 (2011) *
- iPad 1 (2010) *
Logitech Crayon works with all iPads model above that were released in 2018 or later.
See also: Which styluses does GoodNotes 5 support?
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* can't run GoodNotes, but included in the list for the sake of completeness